=>代码
<!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>样式</title>
<style type="text/css">
#out{
width: 90%;
min-width: 764px;
margin: auto; /*使out居中*/
}
#header{
height: 120px;
background-color:#669966;
}
#left_menu{
float: left;
height: 380px;
width: 20%;
background-color:#CCCCCC;
}
#right_main{
float: right;
height: 380px;
width: 80%;
background-color:#CCCCFF;
}
#footer{
height: 80px;
clear: all; /*清除左右两边浮动*/
background-color:#666666;
}
</style>
</head>
<body>
<div id="out">
<div id="header">
头部
</div>
<div id="left_menu">
左边菜单
</div>
<div id="right_main">
主体内容
</div>
<div id="footer">
尾部
</div>
</div>
</body>
</html>