<!DOCTYPE html>
<html>
<head>
<title></title>
<style type="text/css">
#div1{width:100px;
height:500px;
background: aqua;}
li{list-style-type: none;
margin-left: 0px;
text-align: left;
text-indent: -20px;}
li:hover{
background:red;
}
</style>
<script type="text/javascript">
function show(){
var node=document.getElementById(‘div1‘);
if(node.style.display=="block"){
node.style.display="none";
}else{
node.style.display="block";
}
}
</script>
</head>
<body>
<input type="button" value="显示/隐藏" onclick="show()">
<div id="div1">
<ul>
<li>php</li>
<li>python</li>
<li>javascript</li>
<li>ruby</li>
<li>php</li>
</ul>
</div>
</body>
</html>原文：http://my.oschina.net/dongdong11019/blog/493021