<!doctype html>
<html>
<head>
<meta charset="utf-8">
<style>
body{
margin:0;
padding:0;
font-size:30px;
font-weight:bold
}
div{
text-align:center;
line-height: 50px
}
.left{
width:200px;
height:600px;
background: #ccc;
position: absolute;
left:0px;
top:0px;
}
.main{
margin:0 310px 0 210px;
height:600px;
background: #9cf;
}
.right{
width:300px;
height:600px;
background:#fcc;
position: absolute;
right: 0px;
top:0px;
}
</style>
</head>
<body>
<div class="left">200px</div>
<div class="main">lerm</div>
<div class="right">300px</div>
</doby>
</html>
原文：http://www.cnblogs.com/xyw521520/p/5352426.html