代码如下：
<!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 }
#xianshi{ width:130px; height:30px; border:1px solid #666; margin-left:400px; text-align:center; vertical-align:middle; line-height:30px; margin-top:50px}
#xianshi:hover{ cursor:pointer}
.xiang{ width:130px; height:30px; border:1px solid #666; text-align:center; margin-left:400px; line-height:30px; vertical-align:middle}
.xiang:hover{ cursor:pointer; background-color:#93F}
</style>
</head>
<body>
<div>
<div id="xianshi" onclick="xian()"></div>
<div class="xiang" style=" display:none" onclick="huan(this)">111111111</div>
<div class="xiang" style=" display:none" onclick="huan(this)">222222222</div>
<div class="xiang" style=" display:none" onclick="huan(this)">333333333</div>
<div class="xiang" style=" display:none" onclick="huan(this)">444444444</div>
<div class="xiang" style=" display:none" onclick="huan(this)">555555555</div>
<div class="xiang" style=" display:none" onclick="huan(this)">666666666</div>
<div class="xiang" style=" display:none" onclick="huan(this)">777777777</div>
</div>
</body>
<script type="text/javascript">
function xian()
{
var s = document.getElementsByClassName("xiang")
var a = document.getElementById("xianshi")
var nr = a.innerHTML
var nr1 = s.innerHTML
for(i=0;i<s.length;i++)
{
if(s[i].style.display == "none")
{
s[i].style.display = "block"
if(s[i].innerHTML == nr)
{
s[i].style.display = "none"
}
}
else
{
s[i].style.display = "none"
}
}
}
function huan(a)
{
var nr = a.innerHTML
document.getElementById("xianshi").innerHTML = nr
var s = document.getElementsByClassName("xiang")
for(i=0;i<s.length;i++)
{
s[i].style.display = "none"
}
}
</script>
</html>
运行结果如下：
