var myWindow

function openWindow(filename, fenstername, x_coordinate, y_coordinate, breite, hoehe )
   {
	if(navigator.appName == "Netscape")
		{
  	 	myWindow = window.open(filename, "" + fenstername + "", "screenX="+ x_coordinate + ",screenY="+ y_coordinate + ",width=" + breite + ",height=" + hoehe + "");
		}
	else
		{
  		myWindow = window.open(filename, "" + fenstername + "", "top="+ y_coordinate + ",left="+ x_coordinate + ",width=" + breite + ",height=" + hoehe + "");
		}
   }

function closeWindow()
   {
      // Wenn myWindow initialisiert ist
      if (myWindow != null)
      {
         if(myWindow.closed == false)
            myWindow.close()
      }
   }