function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		nav_home_over = newImage("/images/nav-home-over.jpg");
		nav_visionen_over = newImage("/images/nav-visionen-over.jpg");
		nav_urs_stucki_over = newImage("/images/nav-urs-stucki-over.jpg");
		nav_impressionen_over = newImage("/images/nav-impressionen-over.jpg");
		nav_angebot_over = newImage("/images/nav-angebot-over.jpg");
		nav_praxis_over = newImage("/images/nav-praxis-over.jpg");
		nav_links_over = newImage("/images/nav-links-over.jpg");
		preloadFlag = true;
	}
}