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) {
		menu_home_over = newImage("images/menu_home-over.jpg");
		menu_housyouji_info_over = newImage("images/menu_housyouji_info-over.jpg");
		menu_event_over = newImage("images/menu_event-over.jpg");
		menu_kitou_over = newImage("images/menu_kitou-over.jpg");
		menu_event_itiyouraihuku_over = newImage("images/menu_itiyouraihuku-ov.jpg");
		menu_reijyou_over = newImage("images/menu_reijyou-over.jpg");
		menu_houjyoue_over = newImage("images/menu_houjyoue-over.jpg");
		menu_kuyou_over = newImage("images/menu_kuyou-over.jpg");
		menu_keidai_over = newImage("images/menu_keidai-over.jpg");
		preloadFlag = true;
	}
}