<!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">
*{margin:0px auto; padding:0px;}
#xiala{
200px;
height:40px;
border:1px solid #036;
text-align:center;
line-height:40px;
vertical-align:middle;}
#xiala:hover{ cursor:pointer}
.list{
200px;
height:40px;
text-align:center;
line-height:40px;
vertical-align:middle;
border:1px solid #306;
border-top-0px;
display:none;}
.list:hover{
background-color:#60F;
color:#fff;}
</style>
</head>
<body>
<div style="500px; height:500px;">
<div id="xiala" onclick="xianshi()"></div>
<div class="list" onclick="xuanze(this)">11</div>
<div class="list" onclick="xuanze(this)">22</div>
<div class="list" onclick="xuanze(this)">33</div>
<div class="list" onclick="xuanze(this)">44</div>
<div class="list" onclick="xuanze(this)">55</div>
</div>
</body>
<script type="text/javascript">
function xianshi()
{
var list = document.getElementsByClassName("list");
for( var i=0;i<list.length;i++)
{
list[i].style.display="block";
}
}
function xuanze(a)
{
var nr=a.innerHTML;
document.getElementById("xiala").innerHTML=nr;
var list = document.getElementsByClassName("list");
for( var i=0;i<list.length;i++)
{
list[i].style.display="none";
}
}
</script>
</html>