#RB_overlay {
  position: fixed;
  z-index:100;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  min-height:100%;
	background-color: #000;
}

#RB_loading {
  width: 70px;
  margin-left: auto;
  margin-right: auto;
  padding-bottom: 30px;
  text-align: center;
	background: url(../images/redbox_spinner.gif) no-repeat bottom center;
}

#RB_window {
  z-index: 102;
  background-color: #FFFFFF;
  display: block;
  text-align: left;
  overflow: hidden;
  margin: 20px auto 0 auto;
  position:fixed;
}

<!--[if lte IE 6]>
#RB_window {
	position: absolute;
}
<![endif]-->