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) {
		maritachi_over = newImage("images/menu_t/maritachi-over.gif");
		katudou_over = newImage("images/menu_t/katudou-over.gif");
		kaiin_over = newImage("images/menu_t/kaiin-over.gif");
		link_over = newImage("images/menu_t/link-over.gif");
		contact_over = newImage("images/menu_t/contact-over.gif");
		top_g_maritachi_over = newImage("images/menu_t/top_g-maritachi_over.jpg");
		preloadFlag = true;
	}
}