js+div+css的鼠标事件，请教！

在丁丁网（http://www.ddmap.com/）的“热门搜索”下面有这么一个效果：
结婚旅游美食购物娱乐医疗汽车培训保健
比如：鼠标放到“结婚”文字上就显示一个层把关于“结婚”的小类显示在那个层里这个怎么实现呀？
请教各位！！

解决方案 »

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<!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=utf-8" />
<meta http-equiv="Content-Language" content="zh-CN" />
<title>css打造鼠标触发效果</title>
<style type="text/css">
body {
margin: 0;
padding: 0;
color: #000;
font-size: 12px;
line-height: 160%;
text-align: left;
height: 100%;
font-family: '宋体',Tahoma ,arial,verdana,sans-serif,'Lucida Grande','Lucida Sans Unicode';
}
*{ margin:0; padding:0;}
h2,h2 a:link,h2 a:hover,h2 a:visited{
font-size: 14px;
text-decoration: none;
color: #000000;
    }
.kw_from {
padding:20px 0 0 0px;
margin: auto;
height: 300px;
overflow: hidden;
width: 650px;
   }
.kw_from .sbtn{
float:left;
width:80px;
padding: 16px 0 0 0;
}
.kw_from .searchMore{
float:left;
width:80px;
padding: 4px;
}
#searchNav {
width:430px;
float: left;
}
#searchNav #conter1, #searchNav #conter3{
float:left;
width:250px;
}
#searchNav #conter2, #searchNav #conter4{
float:left;
width:180px;
}
#searchNav ul {
padding: 0;
margin: 0;
list-style: none;
}
#searchNav li {
float: left;
}
#searchNav li ul {
display: none;
top: 20px;
}
#searchNav li:hover ul, #searchNav li.over ul {
display: block;
float:left;
}
#searchNav ul li a{
float:left;
display:block;
font-size:12px;
padding:3px;
text-decoration: none;
color: #777;
}
#searchNav ul li a:hover{
background-color:#f4f4f4;
}
#searchNav #jobKw{
width:220px;
height:18px;
}
#searchNav #cityKw{
width:130px;
height:18px;
}
</style>
<script type="text/javascript">
<![CDATA[//>
<!]]>
</script>
</head>
<body>
<div class="kw_from">
  <form action="/search.html" method="get" name="searchForm" id="searchForm" onsubmit="return check()">

        <ul id="searchNav">
        <li id="conter1"><h2>找什么</h2>
     <input id="jobKw" name="jobKw" type="text"  />
           <ul id="conter3">
           <a href="#"><input value="会计"/></a>
           <li><a href="#">网页设计</a></li>
           <li><a href="#">翻译</a></li>
           <li><a href="#">家教</a></li>
           <li><span class="moreCity"><a href="#">更多>> </a></span></li>
        </ul>
     </li>
       <li id="conter2"><h2>在那里</h2>
        <input id="cityKw" name="cityKw" type="text"  />
           <ul id="conter4">
           <li><a href="#">北京</a> </li>
           <li><a href="#">上海</a></li>
           <li><a href="#">广州</a></li>
           <li><a href="#">深圳</a></li>
           <li><a href="#">南京</a></li>
           <li><a href="#">天津</a></li>
           <li><a href="#">杭州</a></li>
           <li><a href="#">成都</a></li>
           <li><a href="#">重庆</a></li>
           <li><a href="#">武汉</a></li>
           <li><a href="#">西安</a></li>
           <li><a href="#">沈阳</a></li>
           <li><span class="moreCity"><a href="#">更多城市>></a></span></li>
           </ul>
      </li>
      </ul>
   <div class="sbtn">
   <input name="submit" type="submit" class="btn4" style="margin:0px 15px 2px 0;" value="搜索工作" />
   </div>
   <div class="searchMore">
        <a href="search_expert.html">高级搜索</a><br /><a href="search_sort.html">分类搜索</a>      </div>
  </form>
</div>
</body>
</html>