<!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> 
原文地址:http://www.cnblogs.com/Tracy-zdy/p/3746645.html