m1_up = new Image();
m1_up.src = "images/m1_up.gif";     
m1_over = new Image();
m1_over.src = "images/m1_over.gif";

m2_up = new Image();
m2_up.src = "images/m2_up.gif";     
m2_over = new Image();
m2_over.src = "images/m2_over.gif";

m3_up = new Image();
m3_up.src = "images/m3_up.gif";     
m3_over = new Image();
m3_over.src = "images/m3_over.gif";

m4_up = new Image();
m4_up.src = "images/m4_up.gif";     
m4_over = new Image();
m4_over.src = "images/m4_over.gif";

fachgebiet_up = new Image();
fachgebiet_up.src = "images/fachgebiet_up.gif";     
fachgebiet_over = new Image();
fachgebiet_over.src = "images/fachgebiet_over.gif";

function Wechsel(Bildname,Bildneu) {
	Bildname.src = Bildneu.src;
}

function Fenster (url) {
	if (document.layers) {
		var larg=screen.availWidth-10;
		var altez=screen.availHeight-20;
	} else {
		var larg=screen.availWidth-2;
		var altez=screen.availHeight;
	}
	xkor=larg/2-300;
	ykor=altez/2-200;

    portrait = window.open(url,"chat","width=600,height=400,left=0,top=0,location=no,menubar=no,resizable=no,status=no,toolbar=no,scrollbars=yes");
	portrait.moveTo(xkor,ykor);
	portrait.focus();
}