div+CSS完成网页布局(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=gb2312" />
<title>无标题文档</title>
<style type="text/css">
body{
margin:0;
padding:0;
}
#head{
height:40px;
background-color:#0033CC;
width:800px;
margin:0;
}
#content{
width:800px;
background:#CCCCCC;
height:200px;
margin:0;
}
#left{
top:40px;
width:150px;
height:200px;
background:#CCCC66;
float:left;
margin:0;
}
#c{
width:500px;
height:200px;
background:#FFFFFF;
margin:0;
}
#right{
width:150px;
height:200px;
background:#339966;
float:right;
margin:0;
}
#foot{
width:800px;
background:#0099CC;
height:40px;
margin:0;
}
</style>
</head>
<body>
<div id="head">head</div>
<div id="content">
  <div id="left">left</div>
  <div id="c">content</div>
  <div id="right">rigth</div>
</div>
<div id="foot">foot</div>
</body>
</html>