js左侧三级菜单导航实例代码

在左侧三级菜单导航想必大家都见到过吧，它的实现过程也并不复杂，下面有个不错的示例，感兴趣的朋友可以了解下
实例代码：
<!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" xml:lang="en" lang="en"> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> 
<title>左侧三级菜单导航-www.jbxue.com</title> 
<style type="text/css"> 
<!-- 
body { 
font-family: Arial, Helvetica, sans-serif; 
font-size: 11px; 
} 
#nav, #nav ul { 
list-style: none; 
background: #F9F9F9; 
font-weight: bold; 
padding: 0px; 
margin: 0px; 
border: solid 1px #CCCCCC; 
border-bottom: 0px; 
 150px; 
text-align: left; 
} 
#nav ul ul{ 
border: solid 1px #CCCCCC; 
border-bottom: 0px; 
} 
#nav a { 
display: block; 
 150px; 
 140px; 
color: #333333; 
text-decoration: none; 
text-align: center; 
border-bottom: solid 1px #CCCCCC; 
text-align: left; 
padding-left: 10px; 
} 
#nav a:hover{ 
color: #336666; 
} 
#nav a.selected{ 
background: url(http://www.jbxue.com/images/common/bb_expand.gif) no-repeat right 50%; 
} 
#nav li { 
line-height: 22px; 
position: relative; 
} 
#nav li ul { 
position: absolute; 
left: -999em; 
 150px; 
font-weight: normal; 
margin: 0px; 
padding: 0px; 
} 
#nav li li { 
 150px; 
} 
#nav li ul a { 
 150px; 
 126px; 
padding: 0px 12px; 
line-height: 22px; 
text-align: left; 
} 
#nav li ul ul { 
margin: 0px 0 0 150px; 
} 
#nav li:hover ul ul,#nav li.sfhover ul ul{ 
left: -999em; 
} 
#nav li:hover ul, #nav li li:hover ul,#nav li.sfhover ul, #nav li li.sfhover ul{ 
left: auto; 
} 
#nav li:hover ul,#nav li.sfhover ul{ 
left: 150px; 
top: 0px; 
} 
#nav li:hover, #nav li.sfhover { 
background: #F5E3C0; 
} 
* html #nav li { 
float: left; 
height: 1%; 
} 
* html #nav li a { 
height: 1%; 
} 
--> 
</style> 
</head> 
<body> 
<p><a href="javascript:history.back()">Back</a></p> 
<ul id="nav"> 
<li><a href="">Home</a></li> 
<li><a href="/aboutme.html">About Me</a></li> 
<li><a class="selected" href="/tutorials.html">Tutorials</a> 
<ul> 
<li><a href="#">Sub Menu 31</a></li> 
<li><a class="selected" href="#">Sub Menu 32</a> 
<ul> 
<li><a href="#">Sub Menu 321</a></li> 
<li><a href="#">Sub Menu 322</a></li> 
<li><a href="#">Sub Menu 323</a></li> 
<li><a href="#">Sub Menu 324</a></li> 
</ul> 
</li> 
<li><a href="#">Sub Menu 33</a></li> 
<li><a href="#">Sub Menu 34</a></li> 
</ul> 
</li> 
<li><a class="selected" href="/gallery/gallery.html">Gallery</a> 
<ul> 
<li><a href="#">Sub Menu 41</a></li> 
<li><a class="selected" href="#">Sub Menu 42</a> 
<ul> 
<li><a href="#">Sub Menu 421</a></li> 
<li><a href="#">Sub Menu 422</a></li> 
<li><a href="#">Sub Menu 423</a></li> 
<li><a href="#">Sub Menu 424</a></li> 
</ul> 
</li> 
<li><a href="#">Sub Menu 43</a></li> 
<li><a href="#">Sub Menu 44</a></li> 
</ul> 
</li> 
<li><a href="#">Contact Me</a></li> 
</ul> 
</body> 
</html> 