var preloadFlag = false;
function preload_rb() {
	if (document.images) {
		rb = newImage ('pix/rb_bigben_zoom.jpg');
		preloadFlag = true;
	}
}

function changeRb(img) {
	if (document.images && (preloadFlag == true)) {
		document.rb.src = img;
	}
}

preload_rb();

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];
		}
	}
}

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