function popup(url) {
 fenster=window.open(url, "RNsystems", "width=500,height=400,resizable=yes,scrollbars=yes");
 fenster.focus();
 return false;
}

function Arrow(id_num,act)
{		
		ob=document.getElementById("red_arrow"+id_num);
		
		ob.style.visibility=act;
	
}