/*  Prototype JavaScript framework, version 1.5.1_rc1
 *  (c) 2005-2007 Sam Stephenson
 *
 *  Prototype is freely distributable under the terms of an MIT-style license.
 *  For details, see the Prototype web site: http://www.prototypejs.org/
 *
/*--------------------------------------------------------------------------*/

var Prototype = {
  Version: '1.5.1_rc1',

  Browser: {
    IE:     !!(window.attachEvent && !window.opera),
    Opera:  !!window.opera,
    WebKit: navigator.userAgent.indexOf('AppleWebKit/') > -1,
    Gecko:  navigator.userAgent.indexOf('Gecko') > -1 && navigator.userAgent.indexOf('KHTML') == -1
  },
  BrowserFeatures: {
    XPath: !!document.evaluate,
    ElementExtensions: !!window.HTMLElement,
    SpecificElementExtensions:
      (document.createElement('div').__proto__ !==
       document.createElement('form').__proto__)
  },

  ScriptFragment: '(?:<script.*?>)((\n|\r|.)*?)(?:<\/script>)',
  emptyFunction: function() {},
  K: function(x) { return x }
}

var Class = {
  create: function() {
    return function() {
      this.initialize.apply(this, arguments);
    }
  }
}

var Abstract = new Object();

Object.extend = function(destination, source) {
  for (var property in source) {
    destination[property] = source[property];
  }
  return destination;
}

Object.extend(Object, {
  inspect: function(object) {
    try {
      if (object === undefined) return 'undefined';
      if (object === null) return 'null';
      return object.inspect ? object.inspect() : object.toString();
    } catch (e) {
      if (e instanceof RangeError) return '...';
      throw e;
    }
  },

  toJSON: function(object) {
    var type = typeof object;
    switch(type) {
      case 'undefined':
      case 'function':
      case 'unknown': return;
      case 'boolean': return object.toString();
    }
    if (object === null) return 'null';
    if (object.toJSON) return object.toJSON();
    if (object.ownerDocument === document) return;
    var results = [];
    for (var property in object) {
      var value = Object.toJSON(object[property]);
      if (value !== undefined)
        results.push(property.toJSON() + ':' + value);
    }
    return '{' + results.join(',') + '}';
  },

  keys: function(object) {
    var keys = [];
    for (var property in object)
      keys.push(property);
    return keys;
  },

  values: function(object) {
    var values = [];
    for (var property in object)
      values.push(object[property]);
    return values;
  },

  clone: function(object) {
    return Object.extend({}, object);
  }
});

Function.prototype.bind = function() {
  var __method = this, args = $A(arguments), object = args.shift();
  return function() {
    return __method.apply(object, args.concat($A(arguments)));
  }
}

Function.prototype.bindAsEventListener = function(object) {
  var __method = this, args = $A(arguments), object = args.shift();
  return function(event) {
    return __method.apply(object, [( event || window.event)].concat(args).concat($A(arguments)));
  }
}

Object.extend(Number.prototype, {
  toColorPart: function() {
    return this.toPaddedString(2, 16);
  },

  succ: function() {
    return this + 1;
  },

  times: function(iterator) {
    $R(0, this, true).each(iterator);
    return this;
  },

  toPaddedString: function(length, radix) {
    var string = this.toString(radix || 10);
    return '0'.times(length - string.length) + string;
  },

  toJSON: function() {
    return isFinite(this) ? this.toString() : 'null';
  }
});

Date.prototype.toJSON = function() {
  return '"' + this.getFullYear() + '-' +
    (this.getMonth() + 1).toPaddedString(2) + '-' +
    this.getDate().toPaddedString(2) + 'T' +
    this.getHours().toPaddedString(2) + ':' +
    this.getMinutes().toPaddedString(2) + ':' +
    this.getSeconds().toPaddedString(2) + '"';
};

var Try = {
  these: function() {
    var returnValue;

    for (var i = 0, length = arguments.length; i < length; i++) {
      var lambda = arguments[i];
      try {
        returnValue = lambda();
        break;
      } catch (e) {}
    }

    return returnValue;
  }
}

/*--------------------------------------------------------------------------*/

var PeriodicalExecuter = Class.create();
PeriodicalExecuter.prototype = {
  initialize: function(callback, frequency) {
    this.callback = callback;
    this.frequency = frequency;
    this.currentlyExecuting = false;

    this.registerCallback();
  },

  registerCallback: function() {
    this.timer = setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
  },

  stop: function() {
    if (!this.timer) return;
    clearInterval(this.timer);
    this.timer = null;
  },

  onTimerEvent: function() {
    if (!this.currentlyExecuting) {
      try {
        this.currentlyExecuting = true;
        this.callback(this);
      } finally {
        this.currentlyExecuting = false;
      }
    }
  }
}
Object.extend(String, {
  interpret: function(value) {
    return value == null ? '' : String(value);
  },
  specialChar: {
    '\b': '\\b',
    '\t': '\\t',
    '\n': '\\n',
    '\f': '\\f',
    '\r': '\\r',
    '\\': '\\\\'
  }
});

Object.extend(String.prototype, {
  gsub: function(pattern, replacement) {
    var result = '', source = this, match;
    replacement = arguments.callee.prepareReplacement(replacement);

    while (source.length > 0) {
      if (match = source.match(pattern)) {
        result += source.slice(0, match.index);
        result += String.interpret(replacement(match));
        source  = source.slice(match.index + match[0].length);
      } else {
        result += source, source = '';
      }
    }
    return result;
  },

  sub: function(pattern, replacement, count) {
    replacement = this.gsub.prepareReplacement(replacement);
    count = count === undefined ? 1 : count;

    return this.gsub(pattern, function(match) {
      if (--count < 0) return match[0];
      return replacement(match);
    });
  },

  scan: function(pattern, iterator) {
    this.gsub(pattern, iterator);
    return this;
  },

  truncate: function(length, truncation) {
    length = length || 30;
    truncation = truncation === undefined ? '...' : truncation;
    return this.length > length ?
      this.slice(0, length - truncation.length) + truncation : this;
  },

  strip: function() {
    return this.replace(/^\s+/, '').replace(/\s+$/, '');
  },

  stripTags: function() {
    return this.replace(/<\/?[^>]+>/gi, '');
  },

  stripScripts: function() {
    return this.replace(new RegExp(Prototype.ScriptFragment, 'img'), '');
  },

  extractScripts: function() {
    var matchAll = new RegExp(Prototype.ScriptFragment, 'img');
    var matchOne = new RegExp(Prototype.ScriptFragment, 'im');
    return (this.match(matchAll) || []).map(function(scriptTag) {
      return (scriptTag.match(matchOne) || ['', ''])[1];
    });
  },

  evalScripts: function() {
    return this.extractScripts().map(function(script) { return eval(script) });
  },

  escapeHTML: function() {
    var self = arguments.callee;
    self.text.data = this;
    return self.div.innerHTML;
  },

  unescapeHTML: function() {
    var div = document.createElement('div');
    div.innerHTML = this.stripTags();
    return div.childNodes[0] ? (div.childNodes.length > 1 ?
      $A(div.childNodes).inject('', function(memo, node) { return memo+node.nodeValue }) :
      div.childNodes[0].nodeValue) : '';
  },

  toQueryParams: function(separator) {
    var match = this.strip().match(/([^?#]*)(#.*)?$/);
    if (!match) return {};

    return match[1].split(separator || '&').inject({}, function(hash, pair) {
      if ((pair = pair.split('='))[0]) {
        var name = decodeURIComponent(pair[0]);
        var value = pair[1] ? decodeURIComponent(pair[1]) : undefined;

        if (hash[name] !== undefined) {
          if (hash[name].constructor != Array)
            hash[name] = [hash[name]];
          if (value) hash[name].push(value);
        }
        else hash[name] = value;
      }
      return hash;
    });
  },

  toArray: function() {
    return this.split('');
  },

  succ: function() {
    return this.slice(0, this.length - 1) +
      String.fromCharCode(this.charCodeAt(this.length - 1) + 1);
  },

  times: function(count) {
    var result = '';
    for (var i = 0; i < count; i++) result += this;
    return result;
  },

  camelize: function() {
    var parts = this.split('-'), len = parts.length;
    if (len == 1) return parts[0];

    var camelized = this.charAt(0) == '-'
      ? parts[0].charAt(0).toUpperCase() + parts[0].substring(1)
      : parts[0];

    for (var i = 1; i < len; i++)
      camelized += parts[i].charAt(0).toUpperCase() + parts[i].substring(1);

    return camelized;
  },

  capitalize: function() {
    return this.charAt(0).toUpperCase() + this.substring(1).toLowerCase();
  },

  underscore: function() {
    return this.gsub(/::/, '/').gsub(/([A-Z]+)([A-Z][a-z])/,'#{1}_#{2}').gsub(/([a-z\d])([A-Z])/,'#{1}_#{2}').gsub(/-/,'_').toLowerCase();
  },

  dasherize: function() {
    return this.gsub(/_/,'-');
  },

  inspect: function(useDoubleQuotes) {
    var escapedString = this.gsub(/[\x00-\x1f\\]/, function(match) {
      var character = String.specialChar[match[0]];
      return character ? character : '\\u00' + match[0].charCodeAt().toPaddedString(2, 16);
    });
    if (useDoubleQuotes) return '"' + escapedString.replace(/"/g, '\\"') + '"';
    return "'" + escapedString.replace(/'/g, '\\\'') + "'";
  },

  toJSON: function() {
    return this.inspect(true);
  },

  evalJSON: function(sanitize) {
    try {
      if (!sanitize || (/^("(\\.|[^"\\\n\r])*?"|[,:{}\[\]0-9.\-+Eaeflnr-u \n\r\t])+?$/.test(this)))
        return eval('(' + this + ')');
    } catch (e) {}
    throw new SyntaxError('Badly formated JSON string: ' + this.inspect());
  },

  include: function(pattern) {
    return this.indexOf(pattern) > -1;
  },

  startsWith: function(pattern) {
    return this.indexOf(pattern) == 0;
  },

  endsWith: function(pattern) {
    return this.lastIndexOf(pattern) == (this.length - pattern.length);
  },

  empty: function() {
    return this == '';
  },

  blank: function() {
    return /^\s*$/.test(this);
  }
});

String.prototype.gsub.prepareReplacement = function(replacement) {
  if (typeof replacement == 'function') return replacement;
  var template = new Template(replacement);
  return function(match) { return template.evaluate(match) };
}

String.prototype.parseQuery = String.prototype.toQueryParams;

Object.extend(String.prototype.escapeHTML, {
  div:  document.createElement('div'),
  text: document.createTextNode('')
});

with (String.prototype.escapeHTML) div.appendChild(text);

var Template = Class.create();
Template.Pattern = /(^|.|\r|\n)(#\{(.*?)\})/;
Template.prototype = {
  initialize: function(template, pattern) {
    this.template = template.toString();
    this.pattern  = pattern || Template.Pattern;
  },

  evaluate: function(object) {
    return this.template.gsub(this.pattern, function(match) {
      var before = match[1];
      if (before == '\\') return match[2];
      return before + String.interpret(object[match[3]]);
    });
  }
}

var $break    = new Object();
var $continue = new Object();

var Enumerable = {
  each: function(iterator) {
    var index = 0;
    try {
      this._each(function(value) {
        iterator(value, index++);
      });
    } catch (e) {
      if (e != $break) throw e;
    }
    return this;
  },

  eachSlice: function(number, iterator) {
    var index = -number, slices = [], array = this.toArray();
    while ((index += number) < array.length)
      slices.push(array.slice(index, index+number));
    return slices.map(iterator);
  },

  all: function(iterator) {
    var result = true;
    this.each(function(value, index) {
      result = result && !!(iterator || Prototype.K)(value, index);
      if (!result) throw $break;
    });
    return result;
  },

  any: function(iterator) {
    var result = false;
    this.each(function(value, index) {
      if (result = !!(iterator || Prototype.K)(value, index))
        throw $break;
    });
    return result;
  },

  collect: function(iterator) {
    var results = [];
    this.each(function(value, index) {
      results.push((iterator || Prototype.K)(value, index));
    });
    return results;
  },

  detect: function(iterator) {
    var result;
    this.each(function(value, index) {
      if (iterator(value, index)) {
        result = value;
        throw $break;
      }
    });
    return result;
  },

  findAll: function(iterator) {
    var results = [];
    this.each(function(value, index) {
      if (iterator(value, index))
        results.push(value);
    });
    return results;
  },

  grep: function(pattern, iterator) {
    var results = [];
    this.each(function(value, index) {
      var stringValue = value.toString();
      if (stringValue.match(pattern))
        results.push((iterator || Prototype.K)(value, index));
    })
    return results;
  },

  include: function(object) {
    var found = false;
    this.each(function(value) {
      if (value == object) {
        found = true;
        throw $break;
      }
    });
    return found;
  },

  inGroupsOf: function(number, fillWith) {
    fillWith = fillWith === undefined ? null : fillWith;
    return this.eachSlice(number, function(slice) {
      while(slice.length < number) slice.push(fillWith);
      return slice;
    });
  },

  inject: function(memo, iterator) {
    this.each(function(value, index) {
      memo = iterator(memo, value, index);
    });
    return memo;
  },

  invoke: function(method) {
    var args = $A(arguments).slice(1);
    return this.map(function(value) {
      return value[method].apply(value, args);
    });
  },

  max: function(iterator) {
    var result;
    this.each(function(value, index) {
      value = (iterator || Prototype.K)(value, index);
      if (result == undefined || value >= result)
        result = value;
    });
    return result;
  },

  min: function(iterator) {
    var result;
    this.each(function(value, index) {
      value = (iterator || Prototype.K)(value, index);
      if (result == undefined || value < result)
        result = value;
    });
    return result;
  },

  partition: function(iterator) {
    var trues = [], falses = [];
    this.each(function(value, index) {
      ((iterator || Prototype.K)(value, index) ?
        trues : falses).push(value);
    });
    return [trues, falses];
  },

  pluck: function(property) {
    var results = [];
    this.each(function(value, index) {
      results.push(value[property]);
    });
    return results;
  },

  reject: function(iterator) {
    var results = [];
    this.each(function(value, index) {
      if (!iterator(value, index))
        results.push(value);
    });
    return results;
  },

  sortBy: function(iterator) {
    return this.map(function(value, index) {
      return {value: value, criteria: iterator(value, index)};
    }).sort(function(left, right) {
      var a = left.criteria, b = right.criteria;
      return a < b ? -1 : a > b ? 1 : 0;
    }).pluck('value');
  },

  toArray: function() {
    return this.map();
  },

  zip: function() {
    var iterator = Prototype.K, args = $A(arguments);
    if (typeof args.last() == 'function')
      iterator = args.pop();

    var collections = [this].concat(args).map($A);
    return this.map(function(value, index) {
      return iterator(collections.pluck(index));
    });
  },

  size: function() {
    return this.toArray().length;
  },

  inspect: function() {
    return '#<Enumerable:' + this.toArray().inspect() + '>';
  }
}

Object.extend(Enumerable, {
  map:     Enumerable.collect,
  find:    Enumerable.detect,
  select:  Enumerable.findAll,
  member:  Enumerable.include,
  entries: Enumerable.toArray
});
var $A = Array.from = function(iterable) {
  if (!iterable) return [];
  if (iterable.toArray) {
    return iterable.toArray();
  } else {
    var results = [];
    for (var i = 0, length = iterable.length; i < length; i++)
      results.push(iterable[i]);
    return results;
  }
}

Object.extend(Array.prototype, Enumerable);

if (!Array.prototype._reverse)
  Array.prototype._reverse = Array.prototype.reverse;

Object.extend(Array.prototype, {
  _each: function(iterator) {
    for (var i = 0, length = this.length; i < length; i++)
      iterator(this[i]);
  },

  clear: function() {
    this.length = 0;
    return this;
  },

  first: function() {
    return this[0];
  },

  last: function() {
    return this[this.length - 1];
  },

  compact: function() {
    return this.select(function(value) {
      return value != null;
    });
  },

  flatten: function() {
    return this.inject([], function(array, value) {
      return array.concat(value && value.constructor == Array ?
        value.flatten() : [value]);
    });
  },

  without: function() {
    var values = $A(arguments);
    return this.select(function(value) {
      return !values.include(value);
    });
  },

  indexOf: function(object) {
    for (var i = 0, length = this.length; i < length; i++)
      if (this[i] == object) return i;
    return -1;
  },

  reverse: function(inline) {
    return (inline !== false ? this : this.toArray())._reverse();
  },

  reduce: function() {
    return this.length > 1 ? this : this[0];
  },

  uniq: function(sorted) {
    return this.inject([], function(array, value, index) {
      if (0 == index || (sorted ? array.last() != value : !array.include(value)))
        array.push(value);
      return array;
    });
  },

  clone: function() {
    return [].concat(this);
  },

  size: function() {
    return this.length;
  },

  inspect: function() {
    return '[' + this.map(Object.inspect).join(', ') + ']';
  },

  toJSON: function() {
    var results = [];
    this.each(function(object) {
      var value = Object.toJSON(object);
      if (value !== undefined) results.push(value);
    });
    return '[' + results.join(',') + ']';
  }
});

Array.prototype.toArray = Array.prototype.clone;

function $w(string) {
  string = string.strip();
  return string ? string.split(/\s+/) : [];
}

if (Prototype.Browser.Opera){
  Array.prototype.concat = function() {
    var array = [];
    for (var i = 0, length = this.length; i < length; i++) array.push(this[i]);
    for (var i = 0, length = arguments.length; i < length; i++) {
      if (arguments[i].constructor == Array) {
        for (var j = 0, arrayLength = arguments[i].length; j < arrayLength; j++)
          array.push(arguments[i][j]);
      } else {
        array.push(arguments[i]);
      }
    }
    return array;
  }
}
var Hash = function(object) {
  if (object instanceof Hash) this.merge(object);
  else Object.extend(this, object || {});
};

Object.extend(Hash, {
  toQueryString: function(obj) {
    var parts = [];
    parts.add = arguments.callee.addPair;

    this.prototype._each.call(obj, function(pair) {
      if (!pair.key) return;
      var value = pair.value;

      if (value && typeof value == 'object') {
        if (value.constructor == Array) value.each(function(value) {
          parts.add(pair.key, value);
        });
        return;
      }
      parts.add(pair.key, value);
    });

    return parts.join('&');
  },

  toJSON: function(object) {
    var results = [];
    this.prototype._each.call(object, function(pair) {
      var value = Object.toJSON(pair.value);
      if (value !== undefined) results.push(pair.key.toJSON() + ':' + value);
    });
    return '{' + results.join(',') + '}';
  }
});

Hash.toQueryString.addPair = function(key, value, prefix) {
  if (value == null) return;
  key = encodeURIComponent(key);
  this.push(key + '=' + (value == null ? '' : encodeURIComponent(value)));
}

Object.extend(Hash.prototype, Enumerable);
Object.extend(Hash.prototype, {
  _each: function(iterator) {
    for (var key in this) {
      var value = this[key];
      if (value && value == Hash.prototype[key]) continue;

      var pair = [key, value];
      pair.key = key;
      pair.value = value;
      iterator(pair);
    }
  },

  keys: function() {
    return this.pluck('key');
  },

  values: function() {
    return this.pluck('value');
  },

  merge: function(hash) {
    return $H(hash).inject(this, function(mergedHash, pair) {
      mergedHash[pair.key] = pair.value;
      return mergedHash;
    });
  },

  remove: function() {
    var result;
    for(var i = 0, length = arguments.length; i < length; i++) {
      var value = this[arguments[i]];
      if (value !== undefined){
        if (result === undefined) result = value;
        else {
          if (result.constructor != Array) result = [result];
          result.push(value)
        }
      }
      delete this[arguments[i]];
    }
    return result;
  },

  toQueryString: function() {
    return Hash.toQueryString(this);
  },

  inspect: function() {
    return '#<Hash:{' + this.map(function(pair) {
      return pair.map(Object.inspect).join(': ');
    }).join(', ') + '}>';
  },

  toJSON: function() {
    return Hash.toJSON(this);
  }
});

function $H(object) {
  if (object instanceof Hash) return object;
  return new Hash(object);
};

// Safari iterates over shadowed properties
if (function() {
  var i = 0, Test = function(value) { this.key = value };
  Test.prototype.key = 'foo';
  for (var property in new Test('bar')) i++;
  return i > 1;
}()) Hash.prototype._each = function(iterator) {
  var cache = [];
  for (var key in this) {
    var value = this[key];
    if ((value && value == Hash.prototype[key]) || cache.include(key)) continue;
    cache.push(key);
    var pair = [key, value];
    pair.key = key;
    pair.value = value;
    iterator(pair);
  }
};
ObjectRange = Class.create();
Object.extend(ObjectRange.prototype, Enumerable);
Object.extend(ObjectRange.prototype, {
  initialize: function(start, end, exclusive) {
    this.start = start;
    this.end = end;
    this.exclusive = exclusive;
  },

  _each: function(iterator) {
    var value = this.start;
    while (this.include(value)) {
      iterator(value);
      value = value.succ();
    }
  },

  include: function(value) {
    if (value < this.start)
      return false;
    if (this.exclusive)
      return value < this.end;
    return value <= this.end;
  }
});

var $R = function(start, end, exclusive) {
  return new ObjectRange(start, end, exclusive);
}

var Ajax = {
  getTransport: function() {
    return Try.these(
      function() {return new XMLHttpRequest()},
      function() {return new ActiveXObject('Msxml2.XMLHTTP')},
      function() {return new ActiveXObject('Microsoft.XMLHTTP')}
    ) || false;
  },

  activeRequestCount: 0
}

Ajax.Responders = {
  responders: [],

  _each: function(iterator) {
    this.responders._each(iterator);
  },

  register: function(responder) {
    if (!this.include(responder))
      this.responders.push(responder);
  },

  unregister: function(responder) {
    this.responders = this.responders.without(responder);
  },

  dispatch: function(callback, request, transport, json) {
    this.each(function(responder) {
      if (typeof responder[callback] == 'function') {
        try {
          responder[callback].apply(responder, [request, transport, json]);
        } catch (e) {}
      }
    });
  }
};

Object.extend(Ajax.Responders, Enumerable);

Ajax.Responders.register({
  onCreate: function() {
    Ajax.activeRequestCount++;
  },
  onComplete: function() {
    Ajax.activeRequestCount--;
  }
});

Ajax.Base = function() {};
Ajax.Base.prototype = {
  setOptions: function(options) {
    this.options = {
      method:       'post',
      asynchronous: true,
      contentType:  'application/x-www-form-urlencoded',
      //encoding:     'UTF-8',
      parameters:   ''
    }
    Object.extend(this.options, options || {});

    this.options.method = this.options.method.toLowerCase();
    if (typeof this.options.parameters == 'string')
      this.options.parameters = this.options.parameters.toQueryParams();
  }
}

Ajax.Request = Class.create();
Ajax.Request.Events =
  ['Uninitialized', 'Loading', 'Loaded', 'Interactive', 'Complete'];

Ajax.Request.prototype = Object.extend(new Ajax.Base(), {
  _complete: false,

  initialize: function(url, options) {
    this.transport = Ajax.getTransport();
    this.setOptions(options);
    this.request(url);
  },

  request: function(url) {
    this.url = url;
    this.method = this.options.method;
    var params = Object.clone(this.options.parameters);

    if (!['get', 'post'].include(this.method)) {
      // simulate other verbs over post
      params['_method'] = this.method;
      this.method = 'post';
    }

    this.parameters = params;

    if (params = Hash.toQueryString(params)) {
      // when GET, append parameters to URL
      if (this.method == 'get')
        this.url += (this.url.include('?') ? '&' : '?') + params;
      else if (/Konqueror|Safari|KHTML/.test(navigator.userAgent))
        params += '&_=';
    }

    try {
      Ajax.Responders.dispatch('onCreate', this, this.transport);

      this.transport.open(this.method.toUpperCase(), this.url,
        this.options.asynchronous);

      if (this.options.asynchronous)
        setTimeout(function() { this.respondToReadyState(1) }.bind(this), 10);

      this.transport.onreadystatechange = this.onStateChange.bind(this);
      this.setRequestHeaders();

      this.body = this.method == 'post' ? (this.options.postBody || params) : null;
      this.transport.send(this.body);

      /* Force Firefox to handle ready state 4 for synchronous requests */
      if (!this.options.asynchronous && this.transport.overrideMimeType)
        this.onStateChange();

    }
    catch (e) {
      this.dispatchException(e);
    }
  },

  onStateChange: function() {
    var readyState = this.transport.readyState;
    if (readyState > 1 && !((readyState == 4) && this._complete))
      this.respondToReadyState(this.transport.readyState);
  },

  setRequestHeaders: function() {
    var headers = {
      'X-Requested-With': 'XMLHttpRequest',
      'X-Prototype-Version': Prototype.Version,
      'Accept': 'text/javascript, text/html, application/xml, text/xml, */*'
    };

    if (this.method == 'post') {
      headers['Content-type'] = this.options.contentType +
        (this.options.encoding ? '; charset=' + this.options.encoding : '');

      /* Force "Connection: close" for older Mozilla browsers to work
       * around a bug where XMLHttpRequest sends an incorrect
       * Content-length header. See Mozilla Bugzilla #246651.
       */
      if (this.transport.overrideMimeType &&
          (navigator.userAgent.match(/Gecko\/(\d{4})/) || [0,2005])[1] < 2005)
            headers['Connection'] = 'close';
    }

    // user-defined headers
    if (typeof this.options.requestHeaders == 'object') {
      var extras = this.options.requestHeaders;

      if (typeof extras.push == 'function')
        for (var i = 0, length = extras.length; i < length; i += 2)
          headers[extras[i]] = extras[i+1];
      else
        $H(extras).each(function(pair) { headers[pair.key] = pair.value });
    }

    for (var name in headers)
      this.transport.setRequestHeader(name, headers[name]);
  },

  success: function() {
    return !this.transport.status
        || (this.transport.status >= 200 && this.transport.status < 300);
  },

  respondToReadyState: function(readyState) {
    var state = Ajax.Request.Events[readyState];
    var transport = this.transport, json = this.evalJSON();

    if (state == 'Complete') {
      try {
        this._complete = true;
        (this.options['on' + this.transport.status]
         || this.options['on' + (this.success() ? 'Success' : 'Failure')]
         || Prototype.emptyFunction)(transport, json);
      } catch (e) {
        this.dispatchException(e);
      }

      if ((this.getHeader('Content-type') || 'text/javascript').strip().
        match(/^(text|application)\/(x-)?(java|ecma)script(;.*)?$/i))
          this.evalResponse();
    }

    try {
      (this.options['on' + state] || Prototype.emptyFunction)(transport, json);
      Ajax.Responders.dispatch('on' + state, this, transport, json);
    } catch (e) {
      this.dispatchException(e);
    }

    if (state == 'Complete') {
      // avoid memory leak in MSIE: clean up
      this.transport.onreadystatechange = Prototype.emptyFunction;
    }
  },

  getHeader: function(name) {
    try {
      return this.transport.getResponseHeader(name);
    } catch (e) { return null }
  },

  evalJSON: function() {
    try {
      var json = this.getHeader('X-JSON');
      return json ? eval('(' + json + ')') : null;
    } catch (e) { return null }
  },

  evalResponse: function() {
    try {
      return eval(this.transport.responseText);
    } catch (e) {
      this.dispatchException(e);
    }
  },

  dispatchException: function(exception) {
    (this.options.onException || Prototype.emptyFunction)(this, exception);
    Ajax.Responders.dispatch('onException', this, exception);
  }
});

Ajax.Updater = Class.create();

Object.extend(Object.extend(Ajax.Updater.prototype, Ajax.Request.prototype), {
  initialize: function(container, url, options) {
    this.container = {
      success: (container.success || container),
      failure: (container.failure || (container.success ? null : container))
    }

    this.transport = Ajax.getTransport();
    this.setOptions(options);

    var onComplete = this.options.onComplete || Prototype.emptyFunction;
    this.options.onComplete = (function(transport, param) {
      this.updateContent();
      onComplete(transport, param);
    }).bind(this);

    this.request(url);
  },

  updateContent: function() {
    var receiver = this.container[this.success() ? 'success' : 'failure'];
    var response = this.transport.responseText;

    if (!this.options.evalScripts) response = response.stripScripts();

    if (receiver = $E(receiver)) {
      if (this.options.insertion)
        new this.options.insertion(receiver, response);
      else
        receiver.update(response);
    }

    if (this.success()) {
      if (this.onComplete)
        setTimeout(this.onComplete.bind(this), 10);
    }
  }
});

Ajax.PeriodicalUpdater = Class.create();
Ajax.PeriodicalUpdater.prototype = Object.extend(new Ajax.Base(), {
  initialize: function(container, url, options) {
    this.setOptions(options);
    this.onComplete = this.options.onComplete;

    this.frequency = (this.options.frequency || 2);
    this.decay = (this.options.decay || 1);

    this.updater = {};
    this.container = container;
    this.url = url;

    this.start();
  },

  start: function() {
    this.options.onComplete = this.updateComplete.bind(this);
    this.onTimerEvent();
  },

  stop: function() {
    this.updater.options.onComplete = undefined;
    clearTimeout(this.timer);
    (this.onComplete || Prototype.emptyFunction).apply(this, arguments);
  },

  updateComplete: function(request) {
    if (this.options.decay) {
      this.decay = (request.responseText == this.lastText ?
        this.decay * this.options.decay : 1);

      this.lastText = request.responseText;
    }
    this.timer = setTimeout(this.onTimerEvent.bind(this),
      this.decay * this.frequency * 1000);
  },

  onTimerEvent: function() {
    this.updater = new Ajax.Updater(this.container, this.url, this.options);
  }
});
function $E(element) {
  if (arguments.length > 1) {
    for (var i = 0, elements = [], length = arguments.length; i < length; i++)
      elements.push($E(arguments[i]));
    return elements;
  }
  if (typeof element == 'string')
    element = document.getElementById(element);
  return Element.extend(element);
}

if (Prototype.BrowserFeatures.XPath) {
  document._getElementsByXPath = function(expression, parentElement) {
    var results = [];
    var query = document.evaluate(expression, $E(parentElement) || document,
      null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
    for (var i = 0, length = query.snapshotLength; i < length; i++)
      results.push(query.snapshotItem(i));
    return results;
  };

  document.getElementsByClassName = function(className, parentElement) {
    var q = ".//*[contains(concat(' ', @class, ' '), ' " + className + " ')]";
    return document._getElementsByXPath(q, parentElement);
  }

} else document.getElementsByClassName = function(className, parentElement) {
  var children = ($E(parentElement) || document.body).getElementsByTagName('*');
  var elements = [], child;
  for (var i = 0, length = children.length; i < length; i++) {
    child = children[i];
    if (Element.hasClassName(child, className))
      elements.push(Element.extend(child));
  }
  return elements;
};

/*--------------------------------------------------------------------------*/

if (!window.Element) var Element = {};

Element.extend = function(element) {
  var F = Prototype.BrowserFeatures;
  if (!element || !element.tagName || element.nodeType == 3 ||
   element._extended || F.SpecificElementExtensions || element == window)
    return element;

  var methods = {}, tagName = element.tagName, cache = Element.extend.cache,
   T = Element.Methods.ByTag;

  // extend methods for all tags (Safari doesn't need this)
  if (!F.ElementExtensions) {
    Object.extend(methods, Element.Methods),
    Object.extend(methods, Element.Methods.Simulated);
  }

  // extend methods for specific tags
  if (T[tagName]) Object.extend(methods, T[tagName]);

  for (var property in methods) {
    var value = methods[property];
    if (typeof value == 'function' && !(property in element))
      element[property] = cache.findOrStore(value);
  }

  element._extended = true;
  return element;
};

Element.extend.cache = {
  findOrStore: function(value) {
    return this[value] = this[value] || function() {
      return value.apply(null, [this].concat($A(arguments)));
    }
  }
};

Element.Methods = {
  visible: function(element) {
    return $E(element).style.display != 'none';
  },

  toggle: function(element) {
    element = $E(element);
    Element[Element.visible(element) ? 'hide' : 'show'](element);
    return element;
  },

  hide: function(element) {
    $E(element).style.display = 'none';
    return element;
  },

  show: function(element) {
    $E(element).style.display = '';
    return element;
  },

  remove: function(element) {
    element = $E(element);
    element.parentNode.removeChild(element);
    return element;
  },

  update: function(element, html) {
    html = typeof html == 'undefined' ? '' : html.toString();
    $E(element).innerHTML = html.stripScripts();
    setTimeout(function() {html.evalScripts()}, 10);
    return element;
  },

  replace: function(element, html) {
    element = $E(element);
    html = typeof html == 'undefined' ? '' : html.toString();
    if (element.outerHTML) {
      element.outerHTML = html.stripScripts();
    } else {
      var range = element.ownerDocument.createRange();
      range.selectNodeContents(element);
      element.parentNode.replaceChild(
        range.createContextualFragment(html.stripScripts()), element);
    }
    setTimeout(function() {html.evalScripts()}, 10);
    return element;
  },

  inspect: function(element) {
    element = $E(element);
    var result = '<' + element.tagName.toLowerCase();
    $H({'id': 'id', 'className': 'class'}).each(function(pair) {
      var property = pair.first(), attribute = pair.last();
      var value = (element[property] || '').toString();
      if (value) result += ' ' + attribute + '=' + value.inspect(true);
    });
    return result + '>';
  },

  recursivelyCollect: function(element, property) {
    element = $E(element);
    var elements = [];
    while (element = element[property])
      if (element.nodeType == 1)
        elements.push(Element.extend(element));
    return elements;
  },

  ancestors: function(element) {
    return $E(element).recursivelyCollect('parentNode');
  },

  descendants: function(element) {
    return $A($E(element).getElementsByTagName('*'));
  },

  immediateDescendants: function(element) {
    if (!(element = $E(element).firstChild)) return [];
    while (element && element.nodeType != 1) element = element.nextSibling;
    if (element) return [element].concat($E(element).nextSiblings());
    return [];
  },

  previousSiblings: function(element) {
    return $E(element).recursivelyCollect('previousSibling');
  },

  nextSiblings: function(element) {
    return $E(element).recursivelyCollect('nextSibling');
  },

  siblings: function(element) {
    element = $E(element);
    return element.previousSiblings().reverse().concat(element.nextSiblings());
  },

  match: function(element, selector) {
    if (typeof selector == 'string')
      selector = new Selector(selector);
    return selector.match($E(element));
  },

  up: function(element, expression, index) {
    var ancestors = $E(element).ancestors();
    return expression ? Selector.findElement(ancestors, expression, index) :
      ancestors[index || 0];
  },

  down: function(element, expression, index) {
    var descendants = $E(element).descendants();
    return expression ? Selector.findElement(descendants, expression, index) :
      descendants[index || 0];
  },

  previous: function(element, expression, index) {
    var previousSiblings = $E(element).previousSiblings();
    return expression ? Selector.findElement(previousSiblings, expression, index) :
      previousSiblings[index || 0];
  },

  next: function(element, expression, index) {
    var nextSiblings = $E(element).nextSiblings();
    return expression ? Selector.findElement(nextSiblings, expression, index) :
      nextSiblings[index || 0];
  },

  getElementsBySelector: function() {
    var args = $A(arguments), element = $E(args.shift());
    return Selector.findChildElements(element, args);
  },

  getElementsByClassName: function(element, className) {
    return document.getElementsByClassName(className, element);
  },

  readAttribute: function(element, name) {
    element = $E(element);
    if (Prototype.Browser.IE) {
      if (!element.attributes) return null;
      var t = Element._attributeTranslations;
      if (t.values[name]) return t.values[name](element, name);
      if (t.names[name])  name = t.names[name];
      var attribute = element.attributes[name];
      return attribute ? attribute.nodeValue : null;
    }
    return element.getAttribute(name);
  },

  getHeight: function(element) {
    return $E(element).getDimensions().height;
  },

  getWidth: function(element) {
    return $E(element).getDimensions().width;
  },

  classNames: function(element) {
    return new Element.ClassNames(element);
  },

  hasClassName: function(element, className) {
    if (!(element = $E(element))) return;
    var elementClassName = element.className;
    if (elementClassName.length == 0) return false;
    if (elementClassName == className ||
        elementClassName.match(new RegExp("(^|\\s)" + className + "(\\s|$)")))
      return true;
    return false;
  },

  addClassName: function(element, className) {
    if (!(element = $E(element))) return;
    Element.classNames(element).add(className);
    return element;
  },

  removeClassName: function(element, className) {
    if (!(element = $E(element))) return;
    Element.classNames(element).remove(className);
    return element;
  },

  toggleClassName: function(element, className) {
    if (!(element = $E(element))) return;
    Element.classNames(element)[element.hasClassName(className) ? 'remove' : 'add'](className);
    return element;
  },

  observe: function() {
    Event.observe.apply(Event, arguments);
    return $A(arguments).first();
  },

  stopObserving: function() {
    Event.stopObserving.apply(Event, arguments);
    return $A(arguments).first();
  },

  // removes whitespace-only text node children
  cleanWhitespace: function(element) {
    element = $E(element);
    var node = element.firstChild;
    while (node) {
      var nextNode = node.nextSibling;
      if (node.nodeType == 3 && !/\S/.test(node.nodeValue))
        element.removeChild(node);
      node = nextNode;
    }
    return element;
  },

  empty: function(element) {
    return $E(element).innerHTML.blank();
  },

  descendantOf: function(element, ancestor) {
    element = $E(element), ancestor = $E(ancestor);
    while (element = element.parentNode)
      if (element == ancestor) return true;
    return false;
  },

  scrollTo: function(element) {
    element = $E(element);
    var pos = Position.cumulativeOffset(element);
    window.scrollTo(pos[0], pos[1]);
    return element;
  },

  getStyle: function(element, style) {
    element = $E(element);
    style = style == 'float' ? 'cssFloat' : style.camelize();
    var value = element.style[style];
    if (!value) {
      var css = document.defaultView.getComputedStyle(element, null);
      value = css ? css[style] : null;
    }
    if (style == 'opacity') return value ? parseFloat(value) : 1.0;
    return value == 'auto' ? null : value;
  },

  getOpacity: function(element) {
    return $E(element).getStyle('opacity');
  },

  setStyle: function(element, styles, camelized) {
    element = $E(element);
    var elementStyle = element.style;

    for (var property in styles)
      if (property == 'opacity') element.setOpacity(styles[property])
      else
        elementStyle[(property == 'float' || property == 'cssFloat') ?
          (elementStyle.styleFloat === undefined ? 'cssFloat' : 'styleFloat') :
          (camelized ? property : property.camelize())] = styles[property];

    return element;
  },

  setOpacity: function(element, value) {
    element = $E(element);
    element.style.opacity = (value == 1 || value === '') ? '' :
      (value < 0.00001) ? 0 : value;
    return element;
  },

  getDimensions: function(element) {
    element = $E(element);
    var display = $E(element).getStyle('display');
    if (display != 'none' && display != null) // Safari bug
      return {width: element.offsetWidth, height: element.offsetHeight};

    // All *Width and *Height properties give 0 on elements with display none,
    // so enable the element temporarily
    var els = element.style;
    var originalVisibility = els.visibility;
    var originalPosition = els.position;
    var originalDisplay = els.display;
    els.visibility = 'hidden';
    els.position = 'absolute';
    els.display = 'block';
    var originalWidth = element.clientWidth;
    var originalHeight = element.clientHeight;
    els.display = originalDisplay;
    els.position = originalPosition;
    els.visibility = originalVisibility;
    return {width: originalWidth, height: originalHeight};
  },

  makePositioned: function(element) {
    element = $E(element);
    var pos = Element.getStyle(element, 'position');
    if (pos == 'static' || !pos) {
      element._madePositioned = true;
      element.style.position = 'relative';
      // Opera returns the offset relative to the positioning context, when an
      // element is position relative but top and left have not been defined
      if (window.opera) {
        element.style.top = 0;
        element.style.left = 0;
      }
    }
    return element;
  },

  undoPositioned: function(element) {
    element = $E(element);
    if (element._madePositioned) {
      element._madePositioned = undefined;
      element.style.position =
        element.style.top =
        element.style.left =
        element.style.bottom =
        element.style.right = '';
    }
    return element;
  },

  makeClipping: function(element) {
    element = $E(element);
    if (element._overflow) return element;
    element._overflow = element.style.overflow || 'auto';
    if ((Element.getStyle(element, 'overflow') || 'visible') != 'hidden')
      element.style.overflow = 'hidden';
    return element;
  },

  undoClipping: function(element) {
    element = $E(element);
    if (!element._overflow) return element;
    element.style.overflow = element._overflow == 'auto' ? '' : element._overflow;
    element._overflow = null;
    return element;
  }
};

Object.extend(Element.Methods, {childOf: Element.Methods.descendantOf});

if (Prototype.Browser.Opera) {
  Element.Methods._getStyle = Element.Methods.getStyle;
  Element.Methods.getStyle = function(element, style) {
    switch(style) {
      case 'left':
      case 'top':
      case 'right':
      case 'bottom':
        if (Element._getStyle(element, 'position') == 'static') return null;
      default: return Element._getStyle(element, style);
    }
  };
}
else if (Prototype.Browser.IE) {
  Element.Methods.getStyle = function(element, style) {
    element = $E(element);
    style = (style == 'float' || style == 'cssFloat') ? 'styleFloat' : style.camelize();
    var value = element.style[style];
    if (!value && element.currentStyle) value = element.currentStyle[style];

    if (style == 'opacity') {
      if (value = (element.getStyle('filter') || '').match(/alpha\(opacity=(.*)\)/))
        if (value[1]) return parseFloat(value[1]) / 100;
      return 1.0;
    }

    if (value == 'auto') {
      if ((style == 'width' || style == 'height') && (element.getStyle('display') != 'none'))
        return element['offset'+style.capitalize()] + 'px';
      return null;
    }
    return value;
  };

  Element.Methods.setOpacity = function(element, value) {
    element = $E(element);
    var filter = element.getStyle('filter'), style = element.style;
    if (value == 1 || value === '') {
      style.filter = filter.replace(/alpha\([^\)]*\)/gi,'');
      return element;
    } else if (value < 0.00001) value = 0;
    style.filter = filter.replace(/alpha\([^\)]*\)/gi, '') +
      'alpha(opacity=' + (value * 100) + ')';
    return element;
  };

  // IE is missing .innerHTML support for TABLE-related elements
  Element.Methods.update = function(element, html) {
    element = $E(element);
    html = typeof html == 'undefined' ? '' : html.toString();
    var tagName = element.tagName.toUpperCase();
    if (['THEAD','TBODY','TR','TD'].include(tagName)) {
      var div = document.createElement('div');
      switch (tagName) {
        case 'THEAD':
        case 'TBODY':
          div.innerHTML = '<table><tbody>' +  html.stripScripts() + '</tbody></table>';
          depth = 2;
          break;
        case 'TR':
          div.innerHTML = '<table><tbody><tr>' +  html.stripScripts() + '</tr></tbody></table>';
          depth = 3;
          break;
        case 'TD':
          div.innerHTML = '<table><tbody><tr><td>' +  html.stripScripts() + '</td></tr></tbody></table>';
          depth = 4;
      }
      $A(element.childNodes).each(function(node) { element.removeChild(node) });
      depth.times(function() { div = div.firstChild });
      $A(div.childNodes).each(function(node) { element.appendChild(node) });
    } else {
      element.innerHTML = html.stripScripts();
    }
    setTimeout(function() { html.evalScripts() }, 10);
    return element;
  }
}
else if (Prototype.Browser.Gecko) {
  Element.Methods.setOpacity = function(element, value) {
    element = $E(element);
    element.style.opacity = (value == 1) ? 0.999999 :
      (value === '') ? '' : (value < 0.00001) ? 0 : value;
    return element;
  };
}

Element._attributeTranslations = {
  names: {
    colspan:   "colSpan",
    rowspan:   "rowSpan",
    valign:    "vAlign",
    datetime:  "dateTime",
    accesskey: "accessKey",
    tabindex:  "tabIndex",
    enctype:   "encType",
    maxlength: "maxLength",
    readonly:  "readOnly",
    longdesc:  "longDesc"
  },
  values: {
    _getAttr: function(element, attribute) {
      return element.getAttribute(attribute, 2);
    },
    _flag: function(element, attribute) {
      return $E(element).hasAttribute(attribute) ? attribute : null;
    },
    style: function(element) {
      return element.style.cssText.toLowerCase();
    },
    title: function(element) {
      var node = element.getAttributeNode('title');
      return node.specified ? node.nodeValue : null;
    }
  }
};

(function() {
  Object.extend(this, {
    href: this._getAttr,
    src:  this._getAttr,
    disabled: this._flag,
    checked:  this._flag,
    readonly: this._flag,
    multiple: this._flag
  });
}).call(Element._attributeTranslations.values);

Element.Methods.Simulated = {
  hasAttribute: function(element, attribute) {
    var t = Element._attributeTranslations, node;
    attribute = t.names[attribute] || attribute;
    node = $E(element).getAttributeNode(attribute);
    return node && node.specified;
  }
};

Element.Methods.ByTag = {};

Object.extend(Element, Element.Methods);

if (!Prototype.BrowserFeatures.ElementExtensions &&
 document.createElement('div').__proto__) {
  window.HTMLElement = {};
  window.HTMLElement.prototype = document.createElement('div').__proto__;
  Prototype.BrowserFeatures.ElementExtensions = true;
}

Element.hasAttribute = function(element, attribute) {
  if (element.hasAttribute) return element.hasAttribute(attribute);
  return Element.Methods.Simulated.hasAttribute(element, attribute);
};

Element.addMethods = function(methods) {
  var F = Prototype.BrowserFeatures, T = Element.Methods.ByTag;
  if (arguments.length == 2) {
    var tagName = methods;
    methods = arguments[1];
  }

  if (!tagName) Object.extend(Element.Methods, methods || {});
  else {
    if (tagName.constructor == Array) tagName.each(extend);
    else extend(tagName);
  }

  function extend(tagName) {
    tagName = tagName.toUpperCase();
    if (!Element.Methods.ByTag[tagName])
      Element.Methods.ByTag[tagName] = {};
    Object.extend(Element.Methods.ByTag[tagName], methods);
  }

  function copy(methods, destination, onlyIfAbsent) {
    onlyIfAbsent = onlyIfAbsent || false;
    var cache = Element.extend.cache;
    for (var property in methods) {
      var value = methods[property];
      if (!onlyIfAbsent || !(property in destination))
        destination[property] = cache.findOrStore(value);
    }
  }

  function findDOMClass(tagName) {
    var klass;
    var trans = {
      "OPTGROUP": "OptGroup", "TEXTAREA": "TextArea", "P": "Paragraph",
      "FIELDSET": "FieldSet", "UL": "UList", "OL": "OList", "DL": "DList",
      "DIR": "Directory", "H1": "Heading", "H2": "Heading", "H3": "Heading",
      "H4": "Heading", "H5": "Heading", "H6": "Heading", "Q": "Quote",
      "INS": "Mod", "DEL": "Mod", "A": "Anchor", "IMG": "Image", "CAPTION":
      "TableCaption", "COL": "TableCol", "COLGROUP": "TableCol", "THEAD":
      "TableSection", "TFOOT": "TableSection", "TBODY": "TableSection", "TR":
      "TableRow", "TH": "TableCell", "TD": "TableCell", "FRAMESET":
      "FrameSet", "IFRAME": "IFrame"
    };
    if (trans[tagName]) klass = 'HTML' + trans[tagName] + 'Element';
    if (window[klass]) return window[klass];
    klass = 'HTML' + tagName + 'Element';
    if (window[klass]) return window[klass];
    klass = 'HTML' + tagName.capitalize() + 'Element';
    if (window[klass]) return window[klass];

    window[klass] = {};
    window[klass].prototype = document.createElement(tagName).__proto__;
    return window[klass];
  }

  if (F.ElementExtensions) {
    copy(Element.Methods, HTMLElement.prototype);
    copy(Element.Methods.Simulated, HTMLElement.prototype, true);
  }

  if (F.SpecificElementExtensions) {
    for (var tag in Element.Methods.ByTag) {
      var klass = findDOMClass(tag);
      if (typeof klass == "undefined") continue;
      copy(T[tag], klass.prototype);
    }
  }
};

var Toggle = { display: Element.toggle };

/*--------------------------------------------------------------------------*/

Abstract.Insertion = function(adjacency) {
  this.adjacency = adjacency;
}

Abstract.Insertion.prototype = {
  initialize: function(element, content) {
    this.element = $E(element);
    this.content = content.stripScripts();

    if (this.adjacency && this.element.insertAdjacentHTML) {
      try {
        this.element.insertAdjacentHTML(this.adjacency, this.content);
      } catch (e) {
        var tagName = this.element.tagName.toUpperCase();
        if (['TBODY', 'TR'].include(tagName)) {
          this.insertContent(this.contentFromAnonymousTable());
        } else {
          throw e;
        }
      }
    } else {
      this.range = this.element.ownerDocument.createRange();
      if (this.initializeRange) this.initializeRange();
      this.insertContent([this.range.createContextualFragment(this.content)]);
    }

    setTimeout(function() {content.evalScripts()}, 10);
  },

  contentFromAnonymousTable: function() {
    var div = document.createElement('div');
    div.innerHTML = '<table><tbody>' + this.content + '</tbody></table>';
    return $A(div.childNodes[0].childNodes[0].childNodes);
  }
}

var Insertion = new Object();

Insertion.Before = Class.create();
Insertion.Before.prototype = Object.extend(new Abstract.Insertion('beforeBegin'), {
  initializeRange: function() {
    this.range.setStartBefore(this.element);
  },

  insertContent: function(fragments) {
    fragments.each((function(fragment) {
      this.element.parentNode.insertBefore(fragment, this.element);
    }).bind(this));
  }
});

Insertion.Top = Class.create();
Insertion.Top.prototype = Object.extend(new Abstract.Insertion('afterBegin'), {
  initializeRange: function() {
    this.range.selectNodeContents(this.element);
    this.range.collapse(true);
  },

  insertContent: function(fragments) {
    fragments.reverse(false).each((function(fragment) {
      this.element.insertBefore(fragment, this.element.firstChild);
    }).bind(this));
  }
});

Insertion.Bottom = Class.create();
Insertion.Bottom.prototype = Object.extend(new Abstract.Insertion('beforeEnd'), {
  initializeRange: function() {
    this.range.selectNodeContents(this.element);
    this.range.collapse(this.element);
  },

  insertContent: function(fragments) {
    fragments.each((function(fragment) {
      this.element.appendChild(fragment);
    }).bind(this));
  }
});

Insertion.After = Class.create();
Insertion.After.prototype = Object.extend(new Abstract.Insertion('afterEnd'), {
  initializeRange: function() {
    this.range.setStartAfter(this.element);
  },

  insertContent: function(fragments) {
    fragments.each((function(fragment) {
      this.element.parentNode.insertBefore(fragment,
        this.element.nextSibling);
    }).bind(this));
  }
});

/*--------------------------------------------------------------------------*/

Element.ClassNames = Class.create();
Element.ClassNames.prototype = {
  initialize: function(element) {
    this.element = $E(element);
  },

  _each: function(iterator) {
    this.element.className.split(/\s+/).select(function(name) {
      return name.length > 0;
    })._each(iterator);
  },

  set: function(className) {
    this.element.className = className;
  },

  add: function(classNameToAdd) {
    if (this.include(classNameToAdd)) return;
    this.set($A(this).concat(classNameToAdd).join(' '));
  },

  remove: function(classNameToRemove) {
    if (!this.include(classNameToRemove)) return;
    this.set($A(this).without(classNameToRemove).join(' '));
  },

  toString: function() {
    return $A(this).join(' ');
  }
};

Object.extend(Element.ClassNames.prototype, Enumerable);
var Selector = Class.create();

Selector.prototype = {
  initialize: function(expression) {
    this.expression = expression.strip();
    this.compileMatcher();
  },

  compileMatcher: function() {
    // Selectors with namespaced attributes can't use the XPath version
    if (Prototype.BrowserFeatures.XPath && !(/\[[\w-]*?:/).test(this.expression))
      return this.compileXPathMatcher();

    var e = this.expression, ps = Selector.patterns, h = Selector.handlers,
        c = Selector.criteria, le, p, m;

    if (Selector._cache[e]) {
      this.matcher = Selector._cache[e]; return;
    }
    this.matcher = ["this.matcher = function(root) {",
                    "var r = root, h = Selector.handlers, c = false, n;"];

    while (e && le != e && (/\S/).test(e)) {
      le = e;
      for (var i in ps) {
        p = ps[i];
        if (m = e.match(p)) {
          this.matcher.push(typeof c[i] == 'function' ? c[i](m) :
    	      new Template(c[i]).evaluate(m));
          e = e.replace(m[0], '');
          break;
        }
      }
    }

    this.matcher.push("return h.unique(n);\n}");
    eval(this.matcher.join('\n'));
    Selector._cache[this.expression] = this.matcher;
  },

  compileXPathMatcher: function() {
    var e = this.expression, ps = Selector.patterns,
        x = Selector.xpath, le, p, m;

    if (Selector._cache[e]) {
      this.xpath = Selector._cache[e]; return;
    }

    this.matcher = ['.//*'];
    while (e && le != e && (/\S/).test(e)) {
      le = e;
      for (var i in ps) {
        if (m = e.match(ps[i])) {
          this.matcher.push(typeof x[i] == 'function' ? x[i](m) :
            new Template(x[i]).evaluate(m));
          e = e.replace(m[0], '');
          break;
        }
      }
    }

    this.xpath = this.matcher.join('');
    Selector._cache[this.expression] = this.xpath;
  },

  findElements: function(root) {
    root = root || document;
    if (this.xpath) return document._getElementsByXPath(this.xpath, root);
    return this.matcher(root);
  },

  match: function(element) {
    return this.findElements(document).include(element);
  },

  toString: function() {
    return this.expression;
  },

  inspect: function() {
    return "#<Selector:" + this.expression.inspect() + ">";
  }
};

Object.extend(Selector, {
  _cache: {},

  xpath: {
    descendant:   "//*",
    child:        "/*",
    adjacent:     "/following-sibling::*[1]",
    laterSibling: '/following-sibling::*',
    tagName:      function(m) {
      if (m[1] == '*') return '';
      return "[local-name()='" + m[1].toLowerCase() +
             "' or local-name()='" + m[1].toUpperCase() + "']";
    },
    className:    "[contains(concat(' ', @class, ' '), ' #{1} ')]",
    id:           "[@id='#{1}']",
    attrPresence: "[@#{1}]",
    attr: function(m) {
      m[3] = m[5] || m[6];
      return new Template(Selector.xpath.operators[m[2]]).evaluate(m);
    },
    pseudo: function(m) {
      var h = Selector.xpath.pseudos[m[1]];
      if (!h) return '';
      if (typeof h === 'function') return h(m);
      return new Template(Selector.xpath.pseudos[m[1]]).evaluate(m);
    },
    operators: {
      '=':  "[@#{1}='#{3}']",
      '!=': "[@#{1}!='#{3}']",
      '^=': "[starts-with(@#{1}, '#{3}')]",
      '$=': "[substring(@#{1}, (string-length(@#{1}) - string-length('#{3}') + 1))='#{3}']",
      '*=': "[contains(@#{1}, '#{3}')]",
      '~=': "[contains(concat(' ', @#{1}, ' '), ' #{3} ')]",
      '|=': "[contains(concat('-', @#{1}, '-'), '-#{3}-')]"
    },
    pseudos: {
      'first-child': '[not(preceding-sibling::*)]',
      'last-child':  '[not(following-sibling::*)]',
      'only-child':  '[not(preceding-sibling::* or following-sibling::*)]',
      'empty':       "[count(*) = 0 and (count(text()) = 0 or translate(text(), ' \t\r\n', '') = '')]",
      'checked':     "[@checked]",
      'disabled':    "[@disabled]",
      'enabled':     "[not(@disabled)]",
      'not': function(m) {
        if (!m[6]) return '';
        var p = Selector.patterns, x = Selector.xpath;
        for (var i in p) {
          if (mm = m[6].match(p[i])) {
            var ss = typeof x[i] == 'function' ? x[i](mm) : new Template(x[i]).evaluate(mm);
            m[6] = ss.substring(1, ss.length - 1);
            break;
          }
        }
        return "[not(" + m[6] + ")]";
      },
      'nth-child':      function(m) {
        return Selector.xpath.pseudos.nth("(count(./preceding-sibling::*) + 1) ", m);
      },
      'nth-last-child': function(m) {
        return Selector.xpath.pseudos.nth("(count(./following-sibling::*) + 1) ", m);
      },
      'nth-of-type':    function(m) {
        return Selector.xpath.pseudos.nth("position() ", m);
      },
      'nth-last-of-type': function(m) {
        return Selector.xpath.pseudos.nth("(last() + 1 - position()) ", m);
      },
      'first-of-type':  function(m) {
        m[6] = "1"; return Selector.xpath.pseudos['nth-of-type'](m);
      },
      'last-of-type':   function(m) {
        m[6] = "1"; return Selector.xpath.pseudos['nth-last-of-type'](m);
      },
      'only-of-type':   function(m) {
        var p = Selector.xpath.pseudos; return p['first-of-type'](m) + p['last-of-type'](m);
      },
      nth: function(predicate, m) {
        var mm, formula = m[6];
        if (formula == 'even') formula = '2n+0';
        if (formula == 'odd')  formula = '2n+1';
        if (mm = formula.match(/^(\d+)$/)) // digit only
          predicate += "= " + mm[1];
        if (mm = formula.match(/^(\d+)?n(\+(\d+))?/)) { // an+b
          var a = mm[1] ? Number(mm[1]) : 1;
          var b = mm[3] ? Number(mm[3]) : 0;
          predicate += "mod " + a + " = " + b;
        }
        return "[" + predicate + "]";
      }
    }
  },

  criteria: {
    tagName:      'n = h.tagName(n, r, "#{1}", c);   c = false;',
    className:    'n = h.className(n, r, "#{1}", c); c = false;',
    id:           'n = h.id(n, r, "#{1}", c);        c = false;',
    attrPresence: 'n = h.attrPresence(n, r, "#{1}"); c = false;',
    attr: function(m) {
      m[3] = m[5] || m[6];
      return new Template('n = h.attr(n, r, "#{1}", "#{3}", "#{2}"); c = false;').evaluate(m);
    },
    pseudo:       'n = h.pseudo(n, "#{1}", "#{6}", r, c); c = false;',
    descendant:   'c = "descendant";',
    child:        'c = "child";',
    adjacent:     'c = "adjacent";',
    laterSibling: 'c = "laterSibling";'
  },

  patterns: {
    // combinators must be listed first
    // (and descendant needs to be last combinator)
    laterSibling: /^\s*~\s*/,
    child:        /^\s*>\s*/,
    adjacent:     /^\s*\+\s*/,
    descendant:   /^\s/,

    // selectors follow
    tagName:      /^\s*(\*|[\w\-]+)(\b|$)?/,
    id:           /^#([\w\-\*]+)(\b|$)/,
    className:    /^\.([\w\-\*]+)(\b|$)/,
    pseudo:       /^:((first|last|nth|nth-last|only)(-child|-of-type)|empty|checked|(en|dis)abled|not)(\((.*?)\))?(\b|$)/,
    attrPresence: /^\[([\w]+)\]/,
    attr:         /\[((?:[\w-]*:)?[\w-]+)\s*(?:([!^$*~|]?=)\s*((['"])([^\]]*?)\4|([^'"][^\]]*?)))?\]/
  },

  handlers: {
    // UTILITY FUNCTIONS
    // joins two collections
    concat: function(a, b) {
      for (var i = 0, node; node = b[i]; i++)
        a.push(node);
      return a;
    },

    // marks an array of nodes for counting
    mark: function(nodes) {
      for (var i = 0, node; node = nodes[i]; i++)
        node._counted = true;
      return nodes;
    },

    unmark: function(nodes) {
      for (var i = 0, node; node = nodes[i]; i++)
        node._counted = undefined;
      return nodes;
    },

    // mark each child node with its position (for nth calls)
    // "ofType" flag indicates whether we're indexing for nth-of-type
    // rather than nth-child
    index: function(parentNode, reverse, ofType) {
      parentNode._counted = true;
      if (reverse) {
        for (var nodes = parentNode.childNodes, i = nodes.length - 1, j = 1; i >= 0; i--) {
          node = nodes[i];
          if (node.nodeType == 1 && (!ofType || node._counted)) node.nodeIndex = j++;
        }
      } else {
        for (var i = 0, j = 1, nodes = parentNode.childNodes; node = nodes[i]; i++)
          if (node.nodeType == 1 && (!ofType || node._counted)) node.nodeIndex = j++;
      }
    },

    // filters out duplicates and extends all nodes
    unique: function(nodes) {
      if (nodes.length == 0) return nodes;
      var results = [nodes[0]], n;
      nodes[0]._counted = true;
      for (var i = 0, l = nodes.length; i < l; i++) {
        n = nodes[i];
        if (!n._counted) {
          n._counted = true;
          results.push(Element.extend(n));
        }
      }
      return Selector.handlers.unmark(results);
    },

    // COMBINATOR FUNCTIONS
    descendant: function(nodes) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        h.concat(results, Element.descendants(node));
      return results;
    },

    child: function(nodes) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        h.concat(results, Element.immediateDescendants(node));
      return results;
    },

    adjacent: function(nodes) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        var next = this.nextElementSibling(node);
        if (next) results.push(next);
      }
      return results;
    },

    laterSibling: function(nodes) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        h.concat(results, Element.nextSiblings(node));
      return results;
    },

    nextElementSibling: function(node) {
      while (node = node.nextSibling)
	      if (node.nodeType == 1) return node;
      return null;
    },

    previousElementSibling: function(node) {
      while (node = node.previousSibling)
        if (node.nodeType == 1) return node;
      return null;
    },

    // TOKEN FUNCTIONS
    tagName: function(nodes, root, tagName, combinator) {
      tagName = tagName.toUpperCase();
      var results = [], h = Selector.handlers;
      if (nodes) {
        if (combinator) {
          // fastlane for ordinary descendant combinators
          if (combinator == "descendant") {
            for (var i = 0, node; node = nodes[i]; i++)
              h.concat(results, node.getElementsByTagName(tagName));
            return results;
          } else nodes = this[combinator](nodes);
          if (tagName == "*") return nodes;
        }
        for (var i = 0, node; node = nodes[i]; i++)
          if (node.tagName.toUpperCase() == tagName) results.push(node);
        return results;
      } else return root.getElementsByTagName(tagName);
    },

    id: function(nodes, root, id, combinator) {
      var targetNode = $E(id), h = Selector.handlers;
      if (!nodes && root == document) return targetNode ? [targetNode] : [];
      if (nodes) {
        if (combinator) {
          if (combinator == 'child') {
            for (var i = 0, node; node = nodes[i]; i++)
              if (targetNode.parentNode == node) return [targetNode];
          } else if (combinator == 'descendant') {
            for (var i = 0, node; node = nodes[i]; i++)
              if (Element.descendantOf(targetNode, node)) return [targetNode];
          } else if (combinator == 'adjacent') {
            for (var i = 0, node; node = nodes[i]; i++)
              if (Selector.handlers.previousElementSibling(targetNode) == node)
                return [targetNode];
          } else nodes = h[combinator](nodes);
        }
        for (var i = 0, node; node = nodes[i]; i++)
          if (node == targetNode) return [targetNode];
        return [];
      }
      return (targetNode && Element.descendantOf(targetNode, root)) ? [targetNode] : [];
    },

    className: function(nodes, root, className, combinator) {
      if (nodes && combinator) nodes = this[combinator](nodes);
      return Selector.handlers.byClassName(nodes, root, className);
    },

    byClassName: function(nodes, root, className) {
      if (!nodes) nodes = Selector.handlers.descendant([root]);
      var needle = ' ' + className + ' ';
      for (var i = 0, results = [], node, nodeClassName; node = nodes[i]; i++) {
        nodeClassName = node.className;
        if (nodeClassName.length == 0) continue;
        if (nodeClassName == className || (' ' + nodeClassName + ' ').include(needle))
          results.push(node);
      }
      return results;
    },

    attrPresence: function(nodes, root, attr) {
      var results = [];
      for (var i = 0, node; node = nodes[i]; i++)
        if (Element.hasAttribute(node, attr)) results.push(node);
      return results;
    },

    attr: function(nodes, root, attr, value, operator) {
      var handler = Selector.operators[operator], results = [];
      for (var i = 0, node; node = nodes[i]; i++) {
        var nodeValue = Element.readAttribute(node, attr);
        if (nodeValue === null) continue;
        if (handler(nodeValue, value)) results.push(node);
      }
      return results;
    },

    pseudo: function(nodes, name, value, root, combinator) {
      if (combinator) nodes = this[combinator](nodes);
      return Selector.pseudos[name](nodes, value, root);
    }
  },

  pseudos: {
    'first-child': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        if (Selector.handlers.previousElementSibling(node)) continue;
          results.push(node);
      }
      return results;
    },
    'last-child': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        if (Selector.handlers.nextElementSibling(node)) continue;
          results.push(node);
      }
      return results;
    },
    'only-child': function(nodes, value, root) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (!h.previousElementSibling(node) && !h.nextElementSibling(node))
          results.push(node);
      return results;
    },
    'nth-child':        function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root);
    },
    'nth-last-child':   function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root, true);
    },
    'nth-of-type':      function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root, false, true);
    },
    'nth-last-of-type': function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root, true, true);
    },
    'first-of-type':    function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, "1", root, false, true);
    },
    'last-of-type':     function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, "1", root, true, true);
    },
    'only-of-type':     function(nodes, formula, root) {
      var p = Selector.pseudos;
      return p['last-of-type'](p['first-of-type'](nodes, formula, root), formula, root);
    },

    // handles nth(-last)-child, nth(-last)-of-type, and (first|last)-of-type
    nth: function(nodes, formula, root, reverse, ofType) {
      if (formula == 'even') formula = '2n+0';
      if (formula == 'odd')  formula = '2n+1';
      var h = Selector.handlers, results = [], indexed = [], m;
      h.mark(nodes);
      for (var i = 0, node; node = nodes[i]; i++) {
        if (!node.parentNode._counted) {
          h.index(node.parentNode, reverse, ofType);
          indexed.push(node.parentNode);
        }
      }
      if (formula.match(/^\d+$/)) { // just a number
        formula = Number(formula);
        for (var i = 0, node; node = nodes[i]; i++)
          if (node.nodeIndex == formula) results.push(node);
      } else if (m = formula.match(/^(\d+)?n(\+(\d+))?$/)) { // an+b
        var a = m[1] ? Number(m[1]) : 1;
        var b = m[3] ? Number(m[3]) : 0;
        for (var i = 0, node; node = nodes[i]; i++)
          if (node.nodeIndex % a == b) results.push(node);
      }
      h.unmark(nodes);
      h.unmark(indexed);
      return results;
    },

    'empty': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        // IE treats comments as element nodes
        if (node.tagName == '!' || (node.firstChild && !node.innerHTML.match(/^\s*$/))) continue;
        results.push(node);
      }
      return results;
    },

    'not': function(nodes, selector, root) {
      var h = Selector.handlers, exclusions = $A(nodes), selectorType, m;
      for (var i in Selector.patterns) {
        if (m = selector.match(Selector.patterns[i])) {
          selectorType = i; break;
        }
      }
      switch(selectorType) {
        case 'className': case 'tagName': case 'id': // fallthroughs
        case 'attrPresence': exclusions = h[selectorType](exclusions, root, m[1], false); break;
        case 'attr': m[3] = m[5] || m[6]; exclusions = h.attr(exclusions, root, m[1], m[3], m[2]); break;
        case 'pseudo': exclusions = h.pseudo(exclusions, m[1], m[6], root, false); break;
        // only 'simple selectors' (one token) allowed in a :not clause
        default: throw 'Illegal selector in :not clause.';
      }
      h.mark(exclusions);
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (!node._counted) results.push(node);
      h.unmark(exclusions);
      return results;
    },

    'enabled': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (!node.disabled) results.push(node);
      return results;
    },

    'disabled': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (node.disabled) results.push(node);
      return results;
    },

    'checked': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (node.checked) results.push(node);
      return results;
    }
  },

  operators: {
    '=':  function(nv, v) { return nv == v; },
    '!=': function(nv, v) { return nv != v; },
    '^=': function(nv, v) { return nv.startsWith(v); },
    '$=': function(nv, v) { return nv.endsWith(v); },
    '*=': function(nv, v) { return nv.include(v); },
    '~=': function(nv, v) { return (' ' + nv + ' ').include(' ' + v + ' '); },
    '|=': function(nv, v) { return ('-' + nv.toUpperCase() + '-').include('-' + v.toUpperCase() + '-'); }
  },

  matchElements: function(elements, expression) {
    var matches = new Selector(expression).findElements(), h = Selector.handlers;
    h.mark(matches);
    for (var i = 0, results = [], element; element = elements[i]; i++)
      if (element._counted) results.push(element);
    h.unmark(matches);
    return results;
  },

  findElement: function(elements, expression, index) {
    if (typeof expression == 'number') {
      index = expression; expression = false;
    }
    return Selector.matchElements(elements, expression || '*')[index || 0];
  },

  findChildElements: function(element, expressions) {
    var exprs = expressions.join(','), expressions = [];
    exprs.scan(/(([\w#:.~>+()\s-]+|\*|\[.*?\])+)\s*(,|$)/, function(m) {
      expressions.push(m[1].strip());
    });
    var results = [], h = Selector.handlers;
    for (var i = 0, l = expressions.length, selector; i < l; i++) {
      selector = new Selector(expressions[i].strip());
      h.concat(results, selector.findElements(element));
    }
    return (l > 1) ? h.unique(results) : results;
  }
});

function $$E() {
  return Selector.findChildElements(document, $A(arguments));
}
var Form = {
  reset: function(form) {
    $E(form).reset();
    return form;
  },

  serializeElements: function(elements, getHash) {
    var data = elements.inject({}, function(result, element) {
      if (!element.disabled && element.name) {
        var key = element.name, value = $E(element).getValue();
        if (value != null) {
         	if (key in result) {
            if (result[key].constructor != Array) result[key] = [result[key]];
            result[key].push(value);
          }
          else result[key] = value;
        }
      }
      return result;
    });

    return getHash ? data : Hash.toQueryString(data);
  }
};

Form.Methods = {
  serialize: function(form, getHash) {
    return Form.serializeElements(Form.getElements(form), getHash);
  },

  getElements: function(form) {
    return $A($E(form).getElementsByTagName('*')).inject([],
      function(elements, child) {
        if (Form.Element.Serializers[child.tagName.toLowerCase()])
          elements.push(Element.extend(child));
        return elements;
      }
    );
  },

  getInputs: function(form, typeName, name) {
    form = $E(form);
    var inputs = form.getElementsByTagName('input');

    if (!typeName && !name) return $A(inputs).map(Element.extend);

    for (var i = 0, matchingInputs = [], length = inputs.length; i < length; i++) {
      var input = inputs[i];
      if ((typeName && input.type != typeName) || (name && input.name != name))
        continue;
      matchingInputs.push(Element.extend(input));
    }

    return matchingInputs;
  },

  disable: function(form) {
    form = $E(form);
    form.getElements().each(function(element) {
      element.blur();
      element.disabled = 'true';
    });
    return form;
  },

  enable: function(form) {
    form = $E(form);
    form.getElements().each(function(element) {
      element.disabled = '';
    });
    return form;
  },

  findFirstElement: function(form) {
    return $E(form).getElements().find(function(element) {
      return element.type != 'hidden' && !element.disabled &&
        ['input', 'select', 'textarea'].include(element.tagName.toLowerCase());
    });
  },

  focusFirstElement: function(form) {
    form = $E(form);
    form.findFirstElement().activate();
    return form;
  },

  request: function(form, options) {
    form = $E(form), options = Object.clone(options || {});

    var params = options.parameters;
    options.parameters = form.serialize(true);

    if (params) {
      if (typeof params == 'string') params = params.toQueryParams();
      Object.extend(options.parameters, params);
    }

    if (form.hasAttribute('method') && !options.method)
      options.method = form.method;

    return new Ajax.Request(form.action, options);
  }
}

Object.extend(Form, Form.Methods);

/*--------------------------------------------------------------------------*/

Form.Element = {
  focus: function(element) {
    $E(element).focus();
    return element;
  },

  select: function(element) {
    $E(element).select();
    return element;
  }
}

Form.Element.Methods = {
  serialize: function(element) {
    element = $E(element);
    if (!element.disabled && element.name) {
      var value = element.getValue();
      if (value != undefined) {
        var pair = {};
        pair[element.name] = value;
        return Hash.toQueryString(pair);
      }
    }
    return '';
  },

  getValue: function(element) {
    element = $E(element);
    var method = element.tagName.toLowerCase();
    return Form.Element.Serializers[method](element);
  },

  clear: function(element) {
    $E(element).value = '';
    return element;
  },

  present: function(element) {
    return $E(element).value != '';
  },

  activate: function(element) {
    element = $E(element);
    try {
      element.focus();
      if (element.select && (element.tagName.toLowerCase() != 'input' ||
        !['button', 'reset', 'submit'].include(element.type)))
        element.select();
    } catch (e) {}
    return element;
  },

  disable: function(element) {
    element = $E(element);
    element.blur();
    element.disabled = true;
    return element;
  },

  enable: function(element) {
    element = $E(element);
    element.disabled = false;
    return element;
  }
}

Object.extend(Form.Element, Form.Element.Methods);
Object.extend(Element.Methods.ByTag, {
  "FORM":     Object.clone(Form.Methods),
  "INPUT":    Object.clone(Form.Element.Methods),
  "SELECT":   Object.clone(Form.Element.Methods),
  "TEXTAREA": Object.clone(Form.Element.Methods)
});

/*--------------------------------------------------------------------------*/

var Field = Form.Element;
var $F = Form.Element.getValue;

/*--------------------------------------------------------------------------*/

Form.Element.Serializers = {
  input: function(element) {
    switch (element.type.toLowerCase()) {
      case 'checkbox':
      case 'radio':
        return Form.Element.Serializers.inputSelector(element);
      default:
        return Form.Element.Serializers.textarea(element);
    }
  },

  inputSelector: function(element) {
    return element.checked ? element.value : null;
  },

  textarea: function(element) {
    return element.value;
  },

  select: function(element) {
    return this[element.type == 'select-one' ?
      'selectOne' : 'selectMany'](element);
  },

  selectOne: function(element) {
    var index = element.selectedIndex;
    return index >= 0 ? this.optionValue(element.options[index]) : null;
  },

  selectMany: function(element) {
    var values, length = element.length;
    if (!length) return null;

    for (var i = 0, values = []; i < length; i++) {
      var opt = element.options[i];
      if (opt.selected) values.push(this.optionValue(opt));
    }
    return values;
  },

  optionValue: function(opt) {
    // extend element because hasAttribute may not be native
    return Element.extend(opt).hasAttribute('value') ? opt.value : opt.text;
  }
}

/*--------------------------------------------------------------------------*/

Abstract.TimedObserver = function() {}
Abstract.TimedObserver.prototype = {
  initialize: function(element, frequency, callback) {
    this.frequency = frequency;
    this.element   = $E(element);
    this.callback  = callback;

    this.lastValue = this.getValue();
    this.registerCallback();
  },

  registerCallback: function() {
    setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
  },

  onTimerEvent: function() {
    var value = this.getValue();
    var changed = ('string' == typeof this.lastValue && 'string' == typeof value
      ? this.lastValue != value : String(this.lastValue) != String(value));
    if (changed) {
      this.callback(this.element, value);
      this.lastValue = value;
    }
  }
}

Form.Element.Observer = Class.create();
Form.Element.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {
  getValue: function() {
    return Form.Element.getValue(this.element);
  }
});

Form.Observer = Class.create();
Form.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {
  getValue: function() {
    return Form.serialize(this.element);
  }
});

/*--------------------------------------------------------------------------*/

Abstract.EventObserver = function() {}
Abstract.EventObserver.prototype = {
  initialize: function(element, callback) {
    this.element  = $E(element);
    this.callback = callback;

    this.lastValue = this.getValue();
    if (this.element.tagName.toLowerCase() == 'form')
      this.registerFormCallbacks();
    else
      this.registerCallback(this.element);
  },

  onElementEvent: function() {
    var value = this.getValue();
    if (this.lastValue != value) {
      this.callback(this.element, value);
      this.lastValue = value;
    }
  },

  registerFormCallbacks: function() {
    Form.getElements(this.element).each(this.registerCallback.bind(this));
  },

  registerCallback: function(element) {
    if (element.type) {
      switch (element.type.toLowerCase()) {
        case 'checkbox':
        case 'radio':
          Event.observe(element, 'click', this.onElementEvent.bind(this));
          break;
        default:
          Event.observe(element, 'change', this.onElementEvent.bind(this));
          break;
      }
    }
  }
}

Form.Element.EventObserver = Class.create();
Form.Element.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {
  getValue: function() {
    return Form.Element.getValue(this.element);
  }
});

Form.EventObserver = Class.create();
Form.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {
  getValue: function() {
    return Form.serialize(this.element);
  }
});
if (!window.Event) {
  var Event = new Object();
}

Object.extend(Event, {
  KEY_BACKSPACE: 8,
  KEY_TAB:       9,
  KEY_RETURN:   13,
  KEY_ESC:      27,
  KEY_LEFT:     37,
  KEY_UP:       38,
  KEY_RIGHT:    39,
  KEY_DOWN:     40,
  KEY_DELETE:   46,
  KEY_HOME:     36,
  KEY_END:      35,
  KEY_PAGEUP:   33,
  KEY_PAGEDOWN: 34,

  element: function(event) {
    return event.target || event.srcElement;
  },

  isLeftClick: function(event) {
    return (((event.which) && (event.which == 1)) ||
            ((event.button) && (event.button == 1)));
  },

  pointerX: function(event) {
    return event.pageX || (event.clientX +
      (document.documentElement.scrollLeft || document.body.scrollLeft));
  },

  pointerY: function(event) {
    return event.pageY || (event.clientY +
      (document.documentElement.scrollTop || document.body.scrollTop));
  },

  stop: function(event) {
    if (event.preventDefault) {
      event.preventDefault();
      event.stopPropagation();
    } else {
      event.returnValue = false;
      event.cancelBubble = true;
    }
  },

  // find the first node with the given tagName, starting from the
  // node the event was triggered on; traverses the DOM upwards
  findElement: function(event, tagName) {
    var element = Event.element(event);
    while (element.parentNode && (!element.tagName ||
        (element.tagName.toUpperCase() != tagName.toUpperCase())))
      element = element.parentNode;
    return element;
  },

  observers: false,

  _observeAndCache: function(element, name, observer, useCapture) {
    if (!this.observers) this.observers = [];
    if (element.addEventListener) {
      this.observers.push([element, name, observer, useCapture]);
      element.addEventListener(name, observer, useCapture);
    } else if (element.attachEvent) {
      this.observers.push([element, name, observer, useCapture]);
      element.attachEvent('on' + name, observer);
    }
  },

  unloadCache: function() {
    if (!Event.observers) return;
    for (var i = 0, length = Event.observers.length; i < length; i++) {
      Event.stopObserving.apply(this, Event.observers[i]);
      Event.observers[i][0] = null;
    }
    Event.observers = false;
  },

  observe: function(element, name, observer, useCapture) {
    element = $E(element);
    useCapture = useCapture || false;

    if (name == 'keypress' &&
      (Prototype.Browser.WebKit || element.attachEvent))
      name = 'keydown';

    Event._observeAndCache(element, name, observer, useCapture);
  },

  stopObserving: function(element, name, observer, useCapture) {
    element = $E(element);
    useCapture = useCapture || false;

    if (name == 'keypress' &&
        (Prototype.Browser.WebKit || element.attachEvent))
      name = 'keydown';

    if (element.removeEventListener) {
      element.removeEventListener(name, observer, useCapture);
    } else if (element.detachEvent) {
      try {
        element.detachEvent('on' + name, observer);
      } catch (e) {}
    }
  }
});

/* prevent memory leaks in IE */
if (Prototype.Browser.IE)
  Event.observe(window, 'unload', Event.unloadCache, false);
var Position = {
  // set to true if needed, warning: firefox performance problems
  // NOT neeeded for page scrolling, only if draggable contained in
  // scrollable elements
  includeScrollOffsets: false,

  // must be called before calling withinIncludingScrolloffset, every time the
  // page is scrolled
  prepare: function() {
    this.deltaX =  window.pageXOffset
                || document.documentElement.scrollLeft
                || document.body.scrollLeft
                || 0;
    this.deltaY =  window.pageYOffset
                || document.documentElement.scrollTop
                || document.body.scrollTop
                || 0;
  },

  realOffset: function(element) {
    var valueT = 0, valueL = 0;
    do {
      valueT += element.scrollTop  || 0;
      valueL += element.scrollLeft || 0;
      element = element.parentNode;
    } while (element);
    return [valueL, valueT];
  },

  cumulativeOffset: function(element) {
    var valueT = 0, valueL = 0;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;
      element = element.offsetParent;
    } while (element);
    return [valueL, valueT];
  },

  positionedOffset: function(element) {
    var valueT = 0, valueL = 0;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;
      element = element.offsetParent;
      if (element) {
        if(element.tagName=='BODY') break;
        var p = Element.getStyle(element, 'position');
        if (p == 'relative' || p == 'absolute') break;
      }
    } while (element);
    return [valueL, valueT];
  },

  offsetParent: function(element) {
    if (element.offsetParent) return element.offsetParent;
    if (element == document.body) return element;

    while ((element = element.parentNode) && element != document.body)
      if (Element.getStyle(element, 'position') != 'static')
        return element;

    return document.body;
  },

  // caches x/y coordinate pair to use with overlap
  within: function(element, x, y) {
    if (this.includeScrollOffsets)
      return this.withinIncludingScrolloffsets(element, x, y);
    this.xcomp = x;
    this.ycomp = y;
    this.offset = this.cumulativeOffset(element);

    return (y >= this.offset[1] &&
            y <  this.offset[1] + element.offsetHeight &&
            x >= this.offset[0] &&
            x <  this.offset[0] + element.offsetWidth);
  },

  withinIncludingScrolloffsets: function(element, x, y) {
    var offsetcache = this.realOffset(element);

    this.xcomp = x + offsetcache[0] - this.deltaX;
    this.ycomp = y + offsetcache[1] - this.deltaY;
    this.offset = this.cumulativeOffset(element);

    return (this.ycomp >= this.offset[1] &&
            this.ycomp <  this.offset[1] + element.offsetHeight &&
            this.xcomp >= this.offset[0] &&
            this.xcomp <  this.offset[0] + element.offsetWidth);
  },

  // within must be called directly before
  overlap: function(mode, element) {
    if (!mode) return 0;
    if (mode == 'vertical')
      return ((this.offset[1] + element.offsetHeight) - this.ycomp) /
        element.offsetHeight;
    if (mode == 'horizontal')
      return ((this.offset[0] + element.offsetWidth) - this.xcomp) /
        element.offsetWidth;
  },

  page: function(forElement) {
    var valueT = 0, valueL = 0;

    var element = forElement;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;

      // Safari fix
      if (element.offsetParent == document.body)
        if (Element.getStyle(element,'position')=='absolute') break;

    } while (element = element.offsetParent);

    element = forElement;
    do {
      if (!window.opera || element.tagName=='BODY') {
        valueT -= element.scrollTop  || 0;
        valueL -= element.scrollLeft || 0;
      }
    } while (element = element.parentNode);

    return [valueL, valueT];
  },

  clone: function(source, target) {
    var options = Object.extend({
      setLeft:    true,
      setTop:     true,
      setWidth:   true,
      setHeight:  true,
      offsetTop:  0,
      offsetLeft: 0
    }, arguments[2] || {})

    // find page position of source
    source = $E(source);
    var p = Position.page(source);

    // find coordinate system to use
    target = $E(target);
    var delta = [0, 0];
    var parent = null;
    // delta [0,0] will do fine with position: fixed elements,
    // position:absolute needs offsetParent deltas
    if (Element.getStyle(target,'position') == 'absolute') {
      parent = Position.offsetParent(target);
      delta = Position.page(parent);
    }

    // correct by body offsets (fixes Safari)
    if (parent == document.body) {
      delta[0] -= document.body.offsetLeft;
      delta[1] -= document.body.offsetTop;
    }

    // set position
    if(options.setLeft)   target.style.left  = (p[0] - delta[0] + options.offsetLeft) + 'px';
    if(options.setTop)    target.style.top   = (p[1] - delta[1] + options.offsetTop) + 'px';
    if(options.setWidth)  target.style.width = source.offsetWidth + 'px';
    if(options.setHeight) target.style.height = source.offsetHeight + 'px';
  },

  absolutize: function(element) {
    element = $E(element);
    if (element.style.position == 'absolute') return;
    Position.prepare();

    var offsets = Position.positionedOffset(element);
    var top     = offsets[1];
    var left    = offsets[0];
    var width   = element.clientWidth;
    var height  = element.clientHeight;

    element._originalLeft   = left - parseFloat(element.style.left  || 0);
    element._originalTop    = top  - parseFloat(element.style.top || 0);
    element._originalWidth  = element.style.width;
    element._originalHeight = element.style.height;

    element.style.position = 'absolute';
    element.style.top    = top + 'px';
    element.style.left   = left + 'px';
    element.style.width  = width + 'px';
    element.style.height = height + 'px';
  },

  relativize: function(element) {
    element = $E(element);
    if (element.style.position == 'relative') return;
    Position.prepare();

    element.style.position = 'relative';
    var top  = parseFloat(element.style.top  || 0) - (element._originalTop || 0);
    var left = parseFloat(element.style.left || 0) - (element._originalLeft || 0);

    element.style.top    = top + 'px';
    element.style.left   = left + 'px';
    element.style.height = element._originalHeight;
    element.style.width  = element._originalWidth;
  }
}

// Safari returns margins on body which is incorrect if the child is absolutely
// positioned.  For performance reasons, redefine Position.cumulativeOffset for
// KHTML/WebKit only.
if (Prototype.Browser.WebKit) {
  Position.cumulativeOffset = function(element) {
    var valueT = 0, valueL = 0;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;
      if (element.offsetParent == document.body)
        if (Element.getStyle(element, 'position') == 'absolute') break;

      element = element.offsetParent;
    } while (element);

    return [valueL, valueT];
  }
}

Element.addMethods();