HTMLDIV+CSS构成的树型菜单

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />

<title>DIV+CSS构成的树型菜单</title>
<style type="text/css">
body {
margin: 0px;
padding: 0;
font: 12px "Lucida Grande", Verdana, Arial, Helvetica, sans-serif;
background: #FFFFFF;
text-align: center;
}

ul{
margin: 0;
padding: 0;
list-style: none;
}

#treenav {
margin: 10px;
text-align: left;
}

#treenav ul li {
margin: 1px 0;
padding: 0;
font-size: 11px;
}

#treenav ul.expanded {
display: block;
}

#treenav ul.expanded,#treenav ul.collapsed {
margin: 5px 10px;
}

#treenav ul.collapsed {
display: none;
}

.expanded li,.collapsed li{
/*border-bottom: 1px dashed #CCCCCC;*/
200px;
}

.listhead {
font-weight: bold;
display: block;
font-size: 12px;
color: #333333;
background: #F1F1F1;
padding: 3px;
120px;
margin: 1px 0;
}

#treenav a {
text-decoration: none;
color: #666666;
}

#treenav a:hover {
color: #990000;
}

</style>
<script type="text/javascript">
function toggleMenu(id){
element = document.getElementById(id);
element.className = (element.className.toLowerCase() == 'expanded'?'collapsed':'expanded');
}
onload = function() {
toggleMenu('submenuid0');
toggleMenu('submenuid1');
}
</script>

</head>

<body>
<ul id="treenav">
   <li>

<ul>
       <li><a href="somepage" onclick="toggleMenu('submenuid0'); return false;" class="listhead">第一章前言</a>

         <ul class="expanded" id="submenuid0">

     <li><a href="#" onclick="toggleMenu('sub0_submenuid1');">第一节网站设计概述</a>
        <ul class="collapsed" id="sub0_submenuid1">
        <li><a href="#">网页制作一般过程</a></li>
        <li><a href="#">网页设计的价格标准</a></li>
     </ul>
     </li>

     <li><a href="#" onclick="toggleMenu('sub0_submenuid2');">第二节网站设计概述</a>
        <ul class="collapsed" id="sub0_submenuid2">
        <li><a href="#">网页设计的价格标准</a></li>
     </ul>
     </li>

   </ul>

    </li>
   </ul>

<ul>
       <li><a href="somepage" onclick="toggleMenu('submenuid1'); return false;" class="listhead">第一章前言</a>

         <ul class="expanded" id="submenuid1">

     <li><a href="#" onclick="toggleMenu('sub1_submenuid1');">第一节网站设计概述</a>
        <ul class="collapsed" id="sub1_submenuid1">
        <li><a href="#">网页制作一般过程</a></li>
        <li><a href="#">网页制作一般过程</a></li>
        <li><a href="#">网页制作一般过程</a></li>
        <li><a href="#">网页制作一般过程</a></li>
        <li><a href="#">网页设计的价格标准</a></li>
        <li><a href="#">网页设计的价格标准</a></li>
     </ul>
     </li>

     <li><a href="#" onclick="toggleMenu('sub1_submenuid2');">第二节网站设计概述</a>
        <ul class="collapsed" id="sub1_submenuid2">
        <li><a href="#">网页制作一般过程</a></li>
        <li><a href="#">网页制作一般过程</a></li>
        <li><a href="#">网页制作一般过程</a></li>
        <li><a href="#">网页制作一般过程</a></li>
        <li><a href="#">网页设计的价格标准</a></li>
        <li><a href="#">网页设计的价格标准</a></li>
     </ul>
     </li>

   </ul>

    </li>
   </ul>


   </li>
</ul>
</body>
</html>