#mask {
  position:absolute;
  left:0;
  top:0;
  z-index:9000;
  background-color:#000;
  display:none;
}  
#boxes .window, #boxes2 .window, #boxes3 .window {
  position: fixed;
 _position: absolute;
  left:0;
  top:0;
  display:none;
  z-index:9999;
  padding:15px;
}
#boxes #dialog{
width:400px;
background: #ffffff;
}

* html #mask{ /* ie6 hack */
     position: absolute;
     height: expression(document.body.scrollHeight > document.body.offsetHeight ? document.body.scrollHeight : document.body.offsetHeight + 'px');
}

* html #boxes .window{ /* ie6 hack */
position: absolute;
margin-top: expression(0 - parseInt(this.offsetHeight / 2) + (TBWindowMargin = document.documentElement && document.documentElement.scrollTop || document.body.scrollTop) + (document.getElementById('dialog').offsetHeight/2) + 'px');
}

* html #boxes2 .window{ /* ie6 hack */
position: absolute;
margin-top: expression(0 - parseInt(this.offsetHeight / 2) + (TBWindowMargin = document.documentElement && document.documentElement.scrollTop || document.body.scrollTop) + (document.getElementById('dialog2').offsetHeight/2) + 'px');
}

* html #boxes3 .window{ /* ie6 hack */
position: absolute;
margin-top: expression(0 - parseInt(this.offsetHeight / 2) + (TBWindowMargin = document.documentElement && document.documentElement.scrollTop || document.body.scrollTop) + (document.getElementById('dialog2').offsetHeight/2) + 'px');
}