// JavaScript Document

//++++++++++++++++++++++++++++++++++++++++++++++++++++++*
//  ボタンのロールオーバーwithプリロード
//++++++++++++++++++++++++++++++++++++++++++++++++++++++*
//
//　■Muu
//　・MULE_VALENTINE
//　http://mule-valentine.chu.jp/
//　ver1.0 2010/10/23
//　
//++++++++++++++++++++++++++++++++++++++++++++++++++++++*

//++++++++++++++++++++++++++++++++++++++++++++++++++++++*
//  開始
//++++++++++++++++++++++++++++++++++++++++++++++++++++++*

if(window.addEventListener) {
	window.addEventListener("load", rollover, false);
}else if(window.attachEvent) {
	window.attachEvent("onload", rollover);
}else {
	window.onload = rollover;
};

//++++++++++++++++++++++++++++++++++++++++++++++++++++++*
// メイン部
//++++++++++++++++++++++++++++++++++++++++++++++++++++++*

function rollover(){
	if (document.getElementsByTagName('img')){
		var btn = document.getElementsByTagName('img');
		var preload_btn = new Array();	
			
		for (i = 0, len = btn.length; i < len; i++){
			if (btn[i].src.match("_off")){
				var preload_btnOn = btn[i].src.replace("_off", "_on");
				preload_btn[i] = new Image();
				preload_btn[i].src = preload_btnOn;
				
				
				btn[i].onmouseover = function(){
					this.src = this.src.replace("_off", "_on");
				};
				btn[i].onmouseout = function(){
					this.src = this.src.replace("_on", "_off")
				};
			};
		};
	};
};