#mistake {position: absolute; margin: auto; top: 0; left: 0; z-index: 100; width:  100%;}
* html #mistake {background-image: none;} 
#m_window {position: absolute; background: #f9f9f9; border: 8px solid #aaa; overflow: auto; width: 450px; height: 540px; z-index: 150;}
#m_frame {border: 0; overflow: auto; width: 100%; height: 519px;}
* html #m_frame {margin-top: 2px;}