if (document.images) {
	/*hintergründe vorladen*/
	img1 = new Image();
	img2 = new Image();
	img3 = new Image();
	img4 = new Image();

	img1.src = "images/bg1.jpg";
	img2.src = "images/bg2.jpg";
	img3.src = "images/bg3.jpg";
	img4.src = "images/bg4.jpg";
}

function menu_on(el) {el.style.backgroundPosition='bottom';}
function menu_off(el) {el.style.backgroundPosition='top';}
function open_menu(el) {
	document.getElementById('wrapper').style.background='url(images/bg' + el + '.jpg) no-repeat';
	for(u=1;u<=4;u++) {
		var parent_divs_childs=document.getElementById('m' + u).getElementsByTagName("a");
		if(u!=el) {
			if(u==3) document.getElementById('zusatz_kunden').style.display='none';
			for(i=1;i<=4;i++) {	
				if(parent_divs_childs[i]) parent_divs_childs[i].style.display='none';
			}
		}
		else {
			for(i=1;i<=4;i++) {	
				if(u==3) Effect.Appear('zusatz_kunden', { duration: 1.0 });
				//if(parent_divs_childs[i]) parent_divs_childs[i].style.display=howtochange;
				if(parent_divs_childs[i]) Effect.Appear(parent_divs_childs[i], { duration: 1.0 });
			}	
		}
	}
}


function oeffnefenster (url) {
 fenster=window.open(url, "_blank", "width=600,height=400,status=yes,scrollbars=yes,resizable=yes");
 fenster.focus();
 return false;
}