<!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" />
<title>无标题文档</title>
<style type="text/css">
ul,li,span{margin:0;padding:0;}
li{list-style:none;}
body{font-size:12px;}
#nav{width:150px;background:#C99;margin:100px;padding:10px;}
#nav li{line-height:30px;}
.list .subMenu{display:none;}
#nav .list span{padding-left:20px;background:url(jia.gif) 0 3px no-repeat;}
#nav span{padding-left:20px;background:url(jian.gif) 0 3px no-repeat;}
</style>
<script type="text/javascript" src="jquery-1.7.2.min.js"></script>
<script type="text/javascript">
$(function(){
$("#nav li:has(‘ul‘)").click(function(){
if($(this).hasClass(‘list‘))
{
$(this).removeClass("list");
}
else
{
$(this).addClass("list");
}
});
})
</script>
</head>
<body>
<ul id="nav">
<li class="list">
<span>111</span>
<ul class="subMenu">
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
</ul>
</li>
<li class="list">
<span>222</span>
<ul class="subMenu">
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
</ul>
</li>
<li class="list">
<span>333</span>
<ul class="subMenu">
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
</ul>
</li>
</ul>
</body>
</html>
原文：http://www.cnblogs.com/ll-taj/p/5250763.html