#mistake {
  background-image: url(overlay.png);
  position: absolute;
  margin: auto;
  top:  0;
  left: 0;
  z-index: 1000;
  width:  100%;
}

* html #mistake {
  background-image: none;
} 

#m_window {
  position: absolute;
  background: #fff;
  border: 2px solid #aaa;
  border-radius:6px;
  overflow: auto;
  width: 450px;
  min-height: 500px;
  max-height: 600px;
  z-index: 150;
}

/*
* html #m_window {
  left: 50%;
  margin-left: -175px;
}
*/

#m_frame {
  border: 0; 
  overflow: auto;
  width: 100%;
  min-height: 480px;
  max-height: 580px;
}

* html #m_frame {
  margin-top: 7px;
}