function NewWindow(mypage,myname){  
  var Left=(screen.width)?(screen.width-800)/2:100;
  var Top=(screen.height)?(screen.height-540)/2:100;
  var Configuration="'toolbar=1, menubar=yes, scrollbars=yes, location=yes, status=yes, resizable=yes, width=800, height=540, left=" + Left + ", top=" + Top;
  window.open(mypage,myname,Configuration);
}