/* Z-index of #mask must be lower than #boxes .window */
#mask {
  position:absolute;
  top:0px;
  left:0px;
  z-index:9000;
  background-color:#000;
  display:none;
}
  
#boxes .window {
  position:absolute;
  width:440px;
  height:200px;
  display:none;
  z-index:9999;
  padding:40px 20px;
}

/* Customize your modal window here, you can add background image too */
#boxes #dialog {
  width:375px; 
  height:203px;
  color:#000;;
  background-color:transparent;
  background:url(notice.png) no-repeat 0 0;
  
}