看示例吧:
<style type="text/css">
body{
margin:0;
padding:30px 0 0 0;
}
div#menu{
position:absolute; top:0;
left:0;
width:100%;
height:30px;
background-color:#ddd;
}
@media screen{
body>div#menu{
position:fixed;
}
}
* html body{
overflow:hidden;
}
* html div#content{
height:100%;
overflow:auto;
}
</style>
HTML示例: