<!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
runat="server">
<title>JavaScript下拉菜单</title>
<style type="text/css">
* {
padding:0;
margin:0;
}
body {
font-family:verdana, sans-serif;
font-size:small;
}
#navigation, #navigation li ul {
list-style-type:none;
}
#navigation {
margin:20px;
}
#navigation li {
text-align:center;
position:relative;
margin-bottom:5px;
}
#navigation li ul li{
text-align:center;
position:relative;
margin-bottom:0px;
}
#navigation li a:link, #navigation li a:visited {
display:block;
text-decoration:none;
color:#000;
width:150px;
height:80px;
line-height:40px;
padding-left:10px;
}
#navigation li ul li a:link, #navigation li ul li a:visited {
display:block;
text-decoration:none;
color:#000;
width:150px;
height:40px;
line-height:40px;
background:#c5dbf2;
padding-left:10px;
}
#navigation li a:hover {
color:#fff;
background:#2687eb;
}
#navigation li ul li a:hover {
color:#fff;
background:#2687eb;
}
#navigation li ul {
display:none;
position:absolute;
top:0px;
left:160px;
margin-top:0;
width:120px;
}
</style>
<script type="text/javascript">
function displaySubMenu(li) {
var subMenu =
li.getElementsByTagName("ul")[0];
li.style.background =
"#c5dbf2";
subMenu.style.display = "block";
}
function
hideSubMenu(li) {
var subMenu =
li.getElementsByTagName("ul")[0];
subMenu.style.display = "none";
li.style.background = "";
}
</script>
</head>
<body>
<div style="width:200px;
height:500px; background-color:red;">
<ul
id="navigation">
<li onmouseover="displaySubMenu(this)"
onmouseout="hideSubMenu(this)">
<a href="#"><img
src="http://www.jeasyui.com/images/logo1.png"
style="width:50px;height:50px"><br/>栏目3</a>
<ul>
<li>
<a
href="#">栏目3->菜单1</a>
</li>
<li><a href="#">栏目3->菜单2</a></li>
<li>
<a href="#">栏目3->菜单3</a>
</li>
</ul>
</li>
<li onmouseover="displaySubMenu(this)"
onmouseout="hideSubMenu(this)">
<a href="#"><img
src="http://www.jeasyui.com/images/logo1.png"
style="width:50px;height:50px"><br/>栏目3</a>
<ul>
<li><a href="#">菜单3->子菜单1</a></li>
<li><a href="#">菜单3->子菜单2</a></li>
<li><a href="#">菜单3->子菜单3</a></li>
</ul>
</li>
</ul>
<div/>
</body>
</html>
原文：http://www.cnblogs.com/Tracy-zdy/p/3746645.html