Css Tips -解决IE 6不支持 fixed

/**
       解决IE 6不支持 fixed
        IE6 hack
      */
        * html,html body{
            background-image: url("about:blank");
            background-attachment: fixed;
        }
        * html #menu {
            position: absolute;
            bottom: auto;
            top: expression(100+((e=document.documentElement.scrollTop)?e:document.body.scrollTop)+'px');
        }