.overlay_holder{width:100%; height:100%; background:url(../images/overlay_bg.png); behavior: url(iepngfix.htc); position:fixed; top:0px; left:0px; z-index:999}
.overlay_wrapper{width:600px; height:470px; z-index:999; position:fixed; padding:10px}
* html .overlay_holder{position: absolute;
top:expression(eval(document.compatMode &&
document.compatMode=='CSS1Compat') ?
documentElement.scrollTop : document.body.scrollTop);}

* html .overlay_wrapper{position: absolute;
top:expression(eval(document.compatMode &&
document.compatMode=='CSS1Compat') ?
documentElement.scrollTop : document.body.scrollTop);}