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) {
		kannai_over = newImage("image/menu/kannai-over.gif");
		furo_over = newImage("image/menu/furo-over.gif");
		ryouri_over = newImage("image/menu/ryouri-over.gif");
		plan_over = newImage("image/menu/plan-over.gif");
		yoyaku_over = newImage("image/menu/yoyaku-over.gif");
		kotu_over = newImage("image/menu/kotu-over.gif");
		kankou_over = newImage("image/menu/kankou-over.gif");
		home_over = newImage("image/menu/home-over.gif");
		preloadFlag = true;
	}
}