//ロールオーバー処理
function rollover() {
	if (!document.getElementsByTagName) return false;
	var image = document.getElementsByTagName("img");
	for (i=0; i<image.length; i++) {
		if (image[i].getAttribute("src").match(/_off\./)){
	 		image[i].onmouseover = function() {
	 			this.setAttribute("src", this.getAttribute("src").replace("_off.","_on."));
	 		}
	 		image[i].onmouseout = function() {
	 			this.setAttribute("src", this.getAttribute("src").replace("_on.","_off."));
	 		}
		}
	}
}


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