  <div class="x5_nav"> 
   <a href="index.php" class="nav_index<?php if(eregi('index.php',$_SERVER["REQUEST_URI"])){echo ' on';} ?>">首页</a> 
   <a href="play.php" class="nav_music<?php if(eregi('play',$_SERVER["REQUEST_URI"])){echo ' on';} ?>">音乐</a> 
   <a href="video.php" class="nav_video<?php if(eregi('video',$_SERVER["REQUEST_URI"])){echo ' on';} ?>">视频</a> 
   <a href="so.php" class="nav_so<?php if(eregi('so',$_SERVER["REQUEST_URI"])){echo ' on';} ?>">搜索</a> 
   <a href="map.php" class="nav_map<?php if(eregi('map',$_SERVER["REQUEST_URI"])){echo ' on';} ?>">地图</a> 
   <a href="user/index.php" class="nav_user">会员中心</a> 
  </div>