<DOCTYPE html>
<html>
<head>
<script src="http://code.jquery.com/jquery-2.0.3.min.js"></script>
<meta charset="UTF-8">
<style>
.nav{height:40px; width: 100%;background: #E6E6E6;}
.nav ul li{float: left;list-style: none;margin-right: 20px;line-height: 40px;}
.nav ul li a{text-decoration: none; display: block;width: 60px; text-align: center;}
.onNav{font-weight: bold;color:#fff; background: #ccc;}
</style>
</head>
<body>
<div class="nav">
<ul>
<li><a href="#" class="onNav">首页</a></li>
<li><a href="#">博客</a></li>
<li><a href="#">论坛</a></li>
<li><a href="#">关于</a></li>
<li><a href="#">联系</a></li>
</ul>
</div>
<script type="text/javascript">
$(".nav ul li a").click(function(){if($(this).has(".onNav")){
$(this).addClass("onNav").parent("li").siblings("li").find("a").removeClass("onNav");}})
</script>
</body>
</html>
