兼容：IE7,8,FF
Code<style type="text/css">
body{margin:0;padding:0;}
#fixed{position:fixed;top:5em;right:0;background:#000;color:#fff;}
</style>
兼容:ie6
Code<!--[if IE 6]>
<style type="text/css">
html{overflow:hidden;}
body{height:100%; overflow:auto;}
#fixed{position:absolute;right:17px;}
</style>
<![endif]-->
兼容：ie5.5 --
Code<!--[if lt IE 6]>
<style type="text/css">
#fixed{position:absolute;top:expression(eval(document.body.scrollTop + 50));}
</style>
<![endif]-->
