$.fn.smartFloat = function() {

    var position = function(element) {

        var top = element.position().top, pos = element.css("position");

        $(window).scroll(function() {

            var scrolls = $(this).scrollTop();

            if (scrolls > top) {

                if (window.XMLHttpRequest) {

                    element.css({

                        position: "fixed",

                        top: 0

                    });    

                } else {

                    element.css({

                        top: scrolls

                    });    

                }

            }else {

                element.css({

                    position: "absolute",

                    top: top

                });    

            }

        });

    };

    return $(this).each(function() {

        position($(this));                         

    });

};