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) {
		canada_over = newImage("images/gallery_menu/canada-over.jpg");
		japan_over = newImage("images/gallery_menu/japan-over.jpg");
		uk_over = newImage("images/gallery_menu/uk-over.jpg");
		australia_over = newImage("images/gallery_menu/australia-over.jpg");
		usa_over = newImage("images/gallery_menu/usa-over.jpg");
		newzealand_over = newImage("images/gallery_menu/newzealand-over.jpg");
		northerneurope_over = newImage("images/gallery_menu/northerneurope-over.jpg");
		preloadFlag = true;
	}
}