.opaque75 {
  filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, sizingMethod=scale, src='../../../!img/px-ba/opaque75_bg.png');
}
.opaque75[class] {
  background-image:url(../../../!img/px-ba/opaque75_bg.png);
}

#ModalBG {  
  top: 0px;
  left: 0px;
  width: 400px;
  height: 300px;  
  position: absolute;
}

#ModalBG .dialog {
  position: absolute;
}