一个简单的JQ写的tab切换(带有滑块)

<!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>无标题文档</title>
<style type="text/css">
*{
padding: 0;
margin: 0;
}
#tab{
width: 600px;
height: 500px;
border: 4px solid blue;
margin: 0 auto;
position: relative;
}
#tab ul li{
width: 200px;
height: 50px;
float: left;
list-style: none;
/*margin: 6px;*/
text-align: center;
line-height: 50px;
font-size: 30px;
color: white;

}
#tab .con{
width: 580px;
height: 400px;
position: absolute;
top: 70px;
left: 10px;
display: none;
}
#tab .huakuai{
width: 200px;
height: 10px;
background: purple;
position: absolute;
left: 0px;
top: 50px;}
</style>
<script type="text/javascript" src="http://www.w3school.com.cn/jquery/jquery-1.11.1.min.js"></script>
<script type="text/javascript">
$(function(){

$('#tab ul li').mouseover(function() {
// 获得移入的li的序号
var c = $(this).index();
// alert(c);
// 让c号con显示，其他的隐藏
$('#tab .con').eq(c).show().siblings('.con').hide();
// 计算小滑块的left
var top = c*200;
// 让滑块运动
$('#tab .huakuai').stop().animate({'left':top+'px'}, 300)
});

})
</script>
<body>
</head>
<body>
<div id="tab">
<ul>
<li style="background:green;">新闻</li>
<li style="background:orange;">娱乐</li>
<li style="background:blue;">世界杯</li>
</ul>
<div class="con" style='background:green;display:block;'></div>
<div class="con" style='background:orange;'></div>
<div class="con" style='background:blue;'></div>
<div class="huakuai"></div>
</div>
</body>
</html>