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) {
		member_bt_over = newImage("/pc_images/member_bt-over.gif");
		newitem_bt_over = newImage("/pc_images/newitem_bt-over.gif");
		news_bt_over = newImage("/pc_images/news_bt-over.gif");
		shop_bt_over = newImage("/pc_images/shop_bt-over.gif");
		dictionary_bt_over = newImage("/pc_images/dictionary_bt-over.gif");
		message_bt_over = newImage("/pc_images/message_bt-over.gif");
		traffic_bt_over = newImage("/pc_images/traffic_bt-over.gif");
		hall_bt_over = newImage("/pc_images/hall_bt-over.gif");
		access_bt_over = newImage("/pc_images/access_bt-over.gif");
		home_bt_over = newImage("/pc_images/home_bt-over.gif");
		preloadFlag = true;
	}
}