//ボタンのロールオーバー
			function changeNb(arg) {
				if (document.images) {
					rslt = new Image();
					rslt.src = arg;
					return rslt;
				}
			}

			function nbChange() {
				if (document.images && (preloadFlag == true)) {
					for (var i=0; i<nbChange.arguments.length; i+=2) {
					document[nbChange.arguments[i]].src = nbChange.arguments[i+1];
					}
				}
			}

//プリロード
			var preloadFlag = false;
			function preloadImages() {
				if (document.images) {
					nb00_over = changeNb("../img/nb/00_over.gif");
					nb01_over = changeNb("../img/nb/01w_over.gif");
					nb02_over = changeNb("../img/nb/02w_over.gif");
					nb03_over = changeNb("../img/nb/03w_over.gif");
					nb04_over = changeNb("../img/nb/04w_over.gif");
					nb05_over = changeNb("../img/nb/05w_over.gif");
					nb06_over = changeNb("../img/nb/neko_b.gif");
					preloadFlag = true;
				}
			}