本节内容：
jquery实现鼠标经过导航条改变背景图的效果。
例子：
<!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>鼠标滑过导航条改变背景图-www.jb200.com</title>
<style>
*{
margin:0;
padding:0;
}
body{
text-align:center;
background:yellow;
}
#container{
width:962px;
height:auto;
background:url(b3.jpg);
margin:0px auto;
}
#head{
height:100px;
width:100%;
}
.head_ul{
list-style:none;
margin-left:200px;
}
.head_ul li{
float:left;
width:90px;
height:50px;
line-height:40px;
font-size:20px;
margin-top:40px;
background:url(b1.png);
}
.head_ul li a{
text-decoration:none;
}
#main{
width:100%;
height:1500px;
}
#left{
width:30%;
height:100%;
float:left;
}
#right{
width:70%;
height:100%;
float:left;
}
#clear{
clear:both;
}
#foot{
height:100px;
width:100%;
}
</style>
<script src="/js/jquery-1.7.2.js"></script>
<script>
$(function(){
$(".head_ul li").hover(function(){
$(this).css('background','url(b2.png)');
},function(){
$(this).css('background','url(b1.png)');
}
);
});
</script>
</head>
<body>
<div id="container">
<div id="head">
<ul class="head_ul">
<li><a href="#">首页</a></li>
<li><a href="#">脚本学堂</a></li>
<li><a href="#">脚本编程</a></li>
<li><a href="#">php 301重定向</a></li>
<li><a href="#">php 301跳转</a></li>
<li><a href="#">首页</a></li>
</ul>
</div>
<div id="main">
<div id="left"></div>
<div id="right"></div>
<div id="clear"></div>
</div>
<div id="foot"></div>
</div
</body>
</html>