JS+CSS打造可拖动的聊天窗口层

一个可以拖动的聊天窗口层，兼容IE和FF：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
  <meta http-equiv="content-type" content="text/html; charset=gb2312">
  <meta http-equiv="content-script-type" content="text/javascript">
  <meta http-equiv="content-style-type" content="text/css">
  <title>DoDi Chat v1.0 Beta</title>
  <style rel="stylesheet" type="text/css" media="all" />
  
  </style>
  <script language="javascript" type="text/javascript">
  <!--
  function $(d){return document.getElementById(d);}
  function gs(d){var t=$(d);if (t){return t.style;}else{return null;}}
  function gs2(d,a){
    if (d.currentStyle){ 
      var curVal=d.currentStyle[a]
    }else{ 
      var curVal=document.defaultView.getComputedStyle(d, null)[a]
    } 
    return curVal;
  }
  function ChatHidden(){gs("ChatBody").display = "none";}
  function ChatShow(){gs("ChatBody").display = "";}
  function ChatClose(){gs("main").display = "none";}
  function ChatSend(obj){
    var o = obj.ChatValue;
    if (o.value.length>0){
      $("ChatContent").innerHTML += "<strong>Akon说：</strong>"+o.value+"<br/>";
      o.value='';
    }
  }

if  (document.getElementById){
    (
      function(){
        if (window.opera){ document.write("<input type='hidden' id='Q' value=' '>"); }
      
        var n = 500;
        var dragok = false;
        var y,x,d,dy,dx;
        
        function move(e)
        {
          if (!e) e = window.event;
          if (dragok){
            d.style.left = dx + e.clientX - x + "px";
            d.style.top  = dy + e.clientY - y + "px";
            return false;
          }
        }
        
        function down(e){
          if (!e) e = window.event;
          var temp = (typeof e.target != "undefined")?e.target:e.srcElement;
          if (temp.tagName != "HTML"|"BODY" && temp.className != "dragclass"){
            temp = (typeof temp.parentNode != "undefined")?temp.parentNode:temp.parentElement;
          }
          if('TR'==temp.tagName){
            temp = (typeof temp.parentNode != "undefined")?temp.parentNode:temp.parentElement;
            temp = (typeof temp.parentNode != "undefined")?temp.parentNode:temp.parentElement;
            temp = (typeof temp.parentNode != "undefined")?temp.parentNode:temp.parentElement;
          }
        
          if (temp.className == "dragclass"){
            if (window.opera){ document.getElementById("Q").focus(); }
            dragok = true;
            temp.style.zIndex = n++;
            d = temp;
            dx = parseInt(gs2(temp,"left"))|0;
            dy = parseInt(gs2(temp,"top"))|0;
            x = e.clientX;
            y = e.clientY;
            document.onmousemove = move;
            return false;
          }
        }
        
        function up(){
          dragok = false;
          document.onmousemove = null;
        }
        
        document.onmousedown = down;
        document.onmouseup = up;
      
      }
    )();
  }
  -->
  </script>
</head>

</body>
</html>