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) {
		newcomb_15_over = newImage("graphics/newcomb_15-over.jpg");
		newcomb_18_over = newImage("graphics/newcomb_18-over.jpg");
		newcomb_19_over = newImage("graphics/newcomb_19-over.jpg");
		newcomb_22_over = newImage("graphics/newcomb_22-over.jpg");
		arrow_01_over   = newImage("graphics/residential+services_on.gif");
		arrow_02_over   = newImage("graphics/commercial+services_on.gif");
		preloadFlag = true;
	}
}