[CODE]<!DOCTYPE html PUBLIC"
http://www.w3c.org/tr/html4/strict.dtd">
<html>
<head>
<title></title>
<style>
*{margin:0px auto;padding:0px auto}
#bb{background:red}
#aa{WIDTH:1PX;HEIGHT:1PX;overflow:hidden;position:absolute;left:0px;bottom:0px}
</style>
<script language="javascript">
function ab(){
document.getElementById("bb").style.height=(document.getElementById("aa").offsetTop+1)+"px";
}
</script>
</head>
<body onload="ab()" onresize="ab()">
<div id="bb"></div>
<DIV id="aa"></div>
</body></html>[/CODE]
要兼容各种游览器,符合W3C标准,写来写去冒视只有这样了,不知道各位有其它好方法不