window.onload = function () {
	  	navContainer = document.getElementById("nav");
	  	images = navContainer.getElementsByTagName("IMG");
	  	var preloader = "";
	  	for(i in images) {
			if(images[i].nodeName == "IMG" && images[i].className != "active") {
				addEvent(images[i], "mouseover", highliteMenu);
				preloader += images[i].src.replace("_off", "_on") + ",";
				addEvent(images[i], "mouseout", downliteMenu);
			}
		}
		preloadImages(preloader);
	};
	function highliteMenu(evt) {
		obj = getGetTarget(evt);
		if(obj.nodeName == "IMG") {
			obj.src = obj.src.replace("_off", "_on");
		}
	}
	function downliteMenu(evt) {
		obj = getGetTarget(evt);
		if(obj.nodeName == "IMG") {
			obj.src = obj.src.replace("_on", "_off");
		}
	}
	
	
	// Hilfsfunktionen 
	function addEvent(obj, evType, fn){
	  if (obj.addEventListener){
	    obj.addEventListener(evType, fn, false);
	    return true;
	  } else if (obj.attachEvent){
	    var r = obj.attachEvent("on"+evType, fn);
	    return r;
	  } else {
	    return false;
		}
	}
	
	function getGetTarget(evt) {
		if(evt.srcElement) return evt.srcElement;
		else return evt.target;
	}
	function preloadImages() {
		 var d=document; if(d.images){ if(!d.p) d.p=new Array();
	    var i,j=d.p.length,a=preloadImages.arguments; for(i=0; i<a.length; i++)
	    if (a[i].indexOf("#")!=0){ d.p[j]=new Image; d.p[j++].src=a[i];}}
	}
	
function openPopup(url)
{
	window.open('/bild.php?pic='+url,'viewer','toolbar=no,location=no,status=no,menubar=no,scrollbars=no,resizable=yes,width=200,height=200');
}