transparent layer i IE6

jeg bruger filter: Alpha(Opacity=50); på mit layer og der virker også fint i IE5 men i IE6 kan den ikke finde ud af at lavet det transparent

nogen ide til hvordan jeg kan gøre



<script>

//Thumbnail image viewer-
//© Dynamic Drive (www.dynamicdrive.com)
//For full source code, usage terms, and 100's more DHTML scripts, visit http://www.dynamicdrive.com

var ie=document.all
var ns=document.layers
var ns6=document.getElementById&&!document.all

function enlarge(which,e){
//Render image code for IE 4+ and NS6
if (ie||ns6){
crossobj=document.getElementById? document.getElementById("showimage") : document.all.showimage
if (crossobj.style.visibility=="hidden"){
crossobj.style.left=ns6? pageXOffset+e.clientX : document.body.scrollLeft+event.clientX
crossobj.style.top=ns6? pageYOffset+e.clientY : document.body.scrollTop+event.clientY
crossobj.innerHTML='<table cellpadding="0" cellspacing="0"  border="0" height="100%"><tr><td><div style="z-index:5;"><a href="#" onClick=closepreview()><img src="images/close.gif" border="0"></a></div><div id="drag"    style="position:absolute; left: 0px; top:10px; width:200px; height:200px; z-index:1; background-color: #CCCCCC; border: 1px solid #000000; filter: Alpha(Opacity=50);"></div><img src="'+which+'"></td></tr></table>'
crossobj.style.visibility="visible"
}
else
crossobj.style.visibility="hidden"
return false
}
//Render image code for NS 4
else if (document.layers){
if (document.showimage.visibility=="hide"){

}
else
document.showimage.visibility="hide"
return false
}
//if NOT IE 4+ or NS 4, simply display image in full browser window
else
return true
}

function closepreview(){
crossobj.style.visibility="hidden"
}

</script>