function init() {
	preloadNavigationImages();
}

function preloadNavigationImages() {
	var prefix = "images/navigation/hauptnavigation_";
	var preload = new Array();
	for(i=1; i<=11; i++) {
		nr = i < 10 ? "0" + i : i;
		preload[i-1] = new Image();
		preload[i-1].src = prefix + nr + ".gif";
	}
}

function changeImage(img, active) {
	extPos = img.src.lastIndexOf(".");
	offset = active ? 0 : 1;
	img.src = img.src.substring(0, extPos-offset) + (active ? "a" : "") + img.src.substr(extPos);
}

function changeImage2(elementId, imageFileName) {
	img = document.getElementById(elementId);
	pos = img.src.lastIndexOf("/");
	img.src = (pos > -1) ? img.src.substring(0, pos+1) + imageFileName : imageFileName;
}