JS+CSS实现简易实用的滑动门菜单效果

<html>
<head>
<title>简易实用，滑动门</title>
<meta http-equiv="Content-Type" content="text/html; charset=gbk" />
<style type="text/css">
*{margin:0;padding:0;}
a:link,a:visited{text-decoration:none;}
a:hover{text-decoration:none;}
ul{list-style:none;}
.subMenu{background:#333;float:left;padding-top:2px;width:100%;}
.subMenu li{float:left;}
.subMenu li a{display:block;float:left;color:#fff;height:25px;line-height:25px;padding:0 5px;margin-left:2px;}
.subMenu .thisStyle a {background:#fff;color:#000;}
.subContent{clear:both;border:2px solid #000;border-top:none;background:#fff;}
.subContent ul{display:none;padding:15px;line-height:180%;}
</style>
</head>
<body>
 <ul class="subMenu">
  <li class="thisStyle"><a href="javascript:void(0)">目录</a></li>
  <li><a href="javascript:void(0)">列表</a></li>
  <li><a href="javascript:void(0)">产品</a></li>
  <li><a href="javascript:void(0)">新网</a></li>
 </ul>
 <div class="subContent">
  <ul style="display:block;">
  <li><a href="#">111111</a></li>
  <li><a href="#">111111</a></li>
  <li><a href="#">111111</a></li>
  <li><a href="#">111111</a></li>
  </ul>
  <ul>
  <li><a href="#">222222</a></li>
  <li><a href="#">222222</a></li>
  <li><a href="#">222222</a></li>
  <li><a href="#">222222</a></li>
  </ul>
  <ul>
  <li><a href="#">333333</a></li>
  <li><a href="#">333333</a></li>
  <li><a href="#">333333</a></li>
  <li><a href="#">333333</a></li>
  </ul>
  <ul>
  <li><a href="#">444444</a></li>
  <li><a href="#">444444</a></li>
  <li><a href="#">444444</a></li>
  <li><a href="#">444444</a></li>
  </ul>
 </div>
<script>
function $_class(name){
 var elements = document.getElementsByTagName("*");
 for(s=0;s<elements.length;s++){
  if(elements[s].className==name){
   return  elements[s];
  } 
 }
}
//tab effects
var tabList = $_class("subMenu").getElementsByTagName("li")
 tabCon = $_class("subContent").getElementsByTagName("ul");
for(i=0;i<tabList.length;i++){
 (function(){
  var t = i;  
  tabList[t].onmouseover = function(){
   for(o=0;o<tabCon.length;o++){
    tabCon[o].style.display = "none";
    tabList[o].className = "";
    if(t==o){
     this.className = "thisStyle";
     tabCon[o].style.display = "block"; 
    }
   }
  } 
 })() 
}
</script>
</bdoy>
</html>