function getMapSize(mapForm) {

   if (self.innerWidth) {
      frameWidth = self.innerWidth;
      frameHeight = self.innerHeight;
   } else if (document.documentElement && document.documentElement.clientWidth) {
      frameWidth = document.documentElement.clientWidth;
      frameHeight = document.documentElement.clientHeight;
   } else if (document.body) {
      frameWidth = document.body.clientWidth;
      frameHeight = document.body.clientHeight;
   } else {
      frameWidth = 250;
      frameHeight = 250;
   }

   mapForm.width.value = frameWidth;
   mapForm.height.value = frameHeight;

   return false;
}