其实很简单！
<!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=gb2312" />
<title>自适应窗口高度</title>
<style>
*{position:relative;margin:0px;}
html{height: 100%;padding:50px; }
body{height: 100%; }
div {min-height: 100%; background-color:#996600;}
/*以下IE6专用*/
*html div {height: 100%;background-color:#99CC00;}
*html body{height: 100%; }
</style>
</head>
<body>
<div>css自适应窗口高度</div>
</body>
</html>