//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) {
		bth_over = changeNb("../img/bth/bth_o.gif");
		bth_over = changeNb("../img/bth/b01.gif");
		bth_over = changeNb("../img/bth/b02.gif");
		bth_over = changeNb("../img/bth/b03.gif");
		bth_over = changeNb("../img/bth/b04.gif");
		bth_over = changeNb("../img/bth/b05.gif");
		bth_over = changeNb("../img/bth/b08.gif");
		bth_over = changeNb("../img/bth/b10.gif");
		ongo_over = changeNb("../img/nb/ongo_o.gif");
		karuta_over = changeNb("../img/nb/karuta_o.gif");
		yokot_over = changeNb("../img/nb/yokot_o.gif");
		tubu_over = changeNb("../img/nb/tubu_o.gif");
		hime_over = changeNb("../img/nb/hime_o.gif");
		taian_over = changeNb("../img/nb/taian_o.gif");
		nyao_over = changeNb("../img/nb/nyao_o.gif");
		suimo_over = changeNb("../img/nb/suimo_o.gif");
		kojin_over = changeNb("../img/nb/kojin_o.gif");
		preloadFlag = true;
	}
}