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) {
		but1 = newImage("images/was-wir-tun-on.jpg");
		but2 = newImage("images/wie-wir-sind-on.jpg");
		but3 = newImage("images/kontakte-on.jpg");
		but4 = newImage("images/wo-wir-sind-on.jpg");
		but5 = newImage("images/gratisbox-on.jpg");
		but1a = newImage("images/was-wir-tun-ion.jpg");
		but2a = newImage("images/wie-wir-sind-ion.jpg");
		but3a = newImage("images/kontakte-ion.jpg");
		but4a = newImage("images/wo-wir-sind-ion.jpg");
		but5a = newImage("images/gratisbox-ion.jpg");
		preloadFlag = true;
	}
}