<style type="text/css">
#main{
width:98%;
}
#sidebar{
float:left;
width:200px;
background-color:#cc7766;
}
#content{
margin-left:200px;
width:auto;
background-color:#AAbb77;
} </style> <body> <div id="main">
<div id="sidebar">左边</div>
<div id="content">右边</div>
</div> </body>