#GB_overlay {
background-image: url(overlay.png); 
position: absolute;
margin: auto;
top: 0;
left: 0;
z-index: 100;
width:  100%;
height: 100%;
}

#GB_window {
text-align:center;
top: 80px;
left: 0px;
position: absolute;
background: #fff;
border: 1px solid #999;
overflow: auto;
width: 650px;
height: 500px;
z-index: 150;
}

#GB_frame {
margin:0 auto;
border: 0;
overflow: auto;
width: 640px;
height: 480px;
}
#GB_caption {
font: 12px bold helvetica, verdana, sans-serif;
color: #444;
background: #ddd;
padding: 5px;
margin: 2px;
text-align: left;
}

#GB_window img {
position: absolute;
top: 2px;
right: 5px;
cursor: pointer;
cursor: hand;
}