为什么给left设置float:left;right块没有上来呢?
#left{width:800px; height:200px; background:#999; float:left;}
#right{width:120px; height:600px; background:#CCF;}
body>
<div id="wrap">wrap
<div id="header">header</div>
<div id="mainbody">
<div id="left"></div>
<div id="right"></div>
</div>
<div id="footer">footer</div>
</div>