// SwapImage JS
// 画像のON/OFF切り替えの自動処理

// onloadイベントを追加 *Lightbox JS から流用
// Lightbox JS by Lokesh Dhakar - http://www.huddletogether.com/
// addLoadEvent() found at Simon Willison's weblog - http://simon.incutio.com/
function addLoadEvent(func){
	var oldonload = window.onload;
	if (typeof window.onload != 'function'){
		window.onload = func;
		load= 1;
	} else {
		window.onload = function(){
			oldonload();
			func();
		}
		load= 1;
	}
}
//初期設定
function initSwapImage(){
	if(!document.getElementsByTagName) return;
	var imgs = document.getElementsByTagName('img');
	for (var i=0; i<imgs.length; i++){
		if(imgs[i].getAttribute('src').match(/_off\..+?$/)){
			imgs[i].onmouseover = function(){ action(this) }
			imgs[i].onmouseout  = function(){ action(this) }
		}
	}
	function action(imgObj){
		var src = imgObj.getAttribute('src');
		var swap;
		if(src.match(/_on\./)){
			swap = src.replace(/_on\.(.+?)$/, function($0,$1){
				return '_off.'+ $1;
			});
		}else if(src.match(/_off\./)){
			swap = src.replace(/_off\.(.+?)$/, function($0,$1){
				return '_on.'+ $1;
			});
		}else{
			return false;
		}
		imgObj.src = swap;
		return true;
	}
}
addLoadEvent(initSwapImage);