var FensterP = null;
function ShowPhoto (Adresse, width, height) {
  if (FensterP != null) // prevent tabbed browsing (don't use an old window with unappropriate size) 
  	FensterP.close();
  if (ShowPhoto.arguments.length < 4)
	attr="width="+(width+20)+",height="+(height+20)+",location=no,scrollbars=no,status=no";
  else
	attr="width="+(width+40)+",height="+(height+40)+",location=no,scrollbars=yes,resizable=yes,status=no";
  FensterP = window.open(Adresse, "Photo", attr);
  FensterP.focus();
}