function PopUpFenster(link, breite, hoehe, scroll, groesse) 
	{
				
		var win_options = "width=" + breite + ",height=" + hoehe + ",scrollbars=" + scroll + ",resizable=" + groesse;
		a=window.open (link,"fenster",win_options);
		var xposition = screen.width/2 - 400;
		var yposition = screen.height/2 - 300;
		a.focus();
		a.moveTo(xposition,yposition); 

	}