纯JS与CSS实现手风琴折叠展开菜单

<!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=gb2312" />
<title>折叠展开的菜单</title>
</head>
<body><style type="text/css">
.menutitle{
cursor:pointer;
margin-bottom: 5px;
background-color:#ECECFF;
color:#000000;
width:140px;
padding:2px;
text-align:center;
font-weight:bold;
/*/*/border:1px solid #000000;/* */
}
.submenu{
margin-bottom: 0.5em;
}
</style>
<script type="text/javascript">
if (document.getElementById){ //DynamicDrive.com change
document.write('<style type="text/css">\n')
document.write('.submenu{display: none;}\n')
document.write('</style>\n')
}
function SwitchMenu(obj){
if(document.getElementById){
var el = document.getElementById(obj);
var ar = document.getElementById("masterdiv").getElementsByTagName("span"); //DynamicDrive.com change
if(el.style.display != "block"){ //DynamicDrive.com change
for (var i=0; i<ar.length; i++){
if (ar[i].className=="submenu") //DynamicDrive.com change
ar[i].style.display = "none";
}
el.style.display = "block";
}else{
el.style.display = "none";
}
}
}
</script>
<!-- Keep all menus within masterdiv-->
<div id="masterdiv">
<div class="menutitle" onclick="SwitchMenu('sub1')">Site Menu</div>
<span class="submenu" id="sub1">
- <a href="#">What's New</a><br>
- <a href="#">What's hot</a><br>
- <a href="#">Revised Scripts</a><br>
- <a href="#">More Zone</a>
</span>
<div class="menutitle" onclick="SwitchMenu('sub2')">FAQ/Help</div>
<span class="submenu" id="sub2">
- <a href="#">Usage Terms</a><br>
- <a href="#">DHTML FAQs</a><br>
- <a href="#">Scripts FAQs</a>
</span>
<div class="menutitle" onclick="SwitchMenu('sub3')">Help Forum</div>
<span class="submenu" id="sub3">
- <a href="#">Coding Forums</a><br>
</span>
<div class="menutitle" onclick="SwitchMenu('sub4')">Cool Links</div>
<span class="submenu" id="sub4">
- <a href="http://www.javascriptkit.com">JavaScript Kit</a><br>
- <a href="https://www.jb51.net">本站</a><br>
- <a href="http://www.cooltext.com">Cool Text</a><br>
</span>
</div>
</body>
</html>