4.3 选项卡

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
	<style type="text/css">
		*{
			margin: 0px auto;
			padding: 0px;
		}
		#dd{
			 320px;
			height: 40px;
			
		}
		.nkk{
			 80px;
			height: 40px;
			text-align: center;
			line-height: 40px;
			vertical-align: middle;
			float: left;
		}
		.ijj{
			 320px;
			height: 300px;
		}
	</style>
//上面定义出一个样式
</head>

<body>
	<div id="dd">
		<div class="nkk" style="background: red" onClick="Ca('uu')">军事</div>
		<div class="nkk" style="background: green;" onClick="Ca('uk')">新闻</div>
		<div class="nkk" style="background: blue;" onClick="Ca('un')">理论</div>
	</div>
//这上面先写出三个标题
	<div class="ijj" id="uu" style="background: red"></div>
	<div class="ijj" id="uk" style="background: green;display: none"></div>
	<div class="ijj" id="un" style="background: blue;display: none"></div>
//这写出三个选项卡
</body>
	<script type="text/javascript">//然后开始写js 部分
		function Ca(a)
		{
			var pp = document.getElementById(a)
			var div = document.getElementsByClassName("ijj")//找定义
			for(i=0;i<div.length;i++)
				{
					div[i].style.display= "none";
				}
			pp.style.display= "block";
		}
	</script>
</html>
这是一个选项卡的效果，他随着标题的变换而变换