function hide_all()
{
	document.getElementById("menugroup2").style.visibility="hidden";
	document.getElementById("menugroup3").style.visibility="hidden";
	document.getElementById("menugroup4").style.visibility="hidden";
	document.getElementById("menugroup5").style.visibility="hidden";
}

function fenster (uri)
{
	window.open (uri,"_blank","width=400,height=308,top=50,left=50,toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no")
}

function kalender ()
{
	kal = window.open ("kalender.html", "_blank", "width=800, height=220, top=10, left=150, toolbar=no, directories=no, status=no, menubar=no, scrollbars=yes, resizeable=no");
	kal.focus();
}

function plakat ()
{
	plak = window.open ("pop_plakat.html", "_blank", "width=400, height=563, top=10, left=150, toolbar=no, directories=no, status=no, menubar=no, scrollbars=no, resizeable=no");
	plak.focus();
}