div页面居中(上下左右)

	<!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>Special Layout</title>
	<style type="text/css">
	html, body {
	width: 100%;
	height: 100%;
	margin: 0;
	padding: 0;
	}
	body {

	}
	#wrapper {
	position: relative;
	top: 10%;
	margin: 0 auto;
	width: 80%;
	min-width: 400px;
	height: 80%;
	background: #000;
	}
	#left {
	float: left;
	position: relative;
	width: 200px;
	height: 100%;
	margin-right: -200px;
	background: blue;
	overflow: hidden;
	}
	#right {
	position: relative;
	width: auto;
	height: 100%;
	background: green;
	margin-left: 200px;
	overflow: hidden;
	}
	#lefttop {
	width: 100%;
	height: 100px;
	background: red;
	}
	#leftbottom {
	width: 100%;
	background: #0ff;
	height: auto !important;
	height: 9999px;
	}
	#left>#leftbottom {
	position: absolute;
	top: 100px;
	bottom: 0;
	}
	#righttop {
	width: 100%;
	height: 100px;
	background: #f0f;
	}
	#rightbottom {
	width: 100%;
	background: #ff0;
	height: auto !important;
	height: 9999px;
	}
	#right>#rightbottom {
	position: absolute;;
	top: 100px;
	bottom: 0;
	}
	</style>
	</head>
	<body>
	<div id="wrapper">
	<div id="left">
	<div id="lefttop">lefttop</div>
	<div id="leftbottom">leftbottom</div>
	</div>
	<div id="right">
	<div id="righttop">righttop</div>
	<div id="rightbottom">rightbottom</div>
	</div>
	</div>
	</body>
	</html>