function changeRollover() {
	if(document.getElementsByTagName) {
		var images = document.getElementsByTagName("img");
		preImages = new Image();
		preImages.src = "http://www.bsfuji.tv/top/img/happen/happen_000000_00_big.gif";

		for(var i=0; i < images.length; i++) {
			if(images[i].getAttribute("src").match("_small.")) {
				
				images[i].onmouseover = function() {
					var startPos = this.getAttribute("src").indexOf("happen_",0);
					var stopPos = startPos+13;
					var changePos = stopPos+11;
					var nowId = this.getAttribute("src").substring(startPos,stopPos);
					var changeId = document.getElementById(nowId);
					var loadImg = changeId.getAttribute("src").substring(startPos,changePos);
					var exImg = "happen_000000_00_big.gif";
					changeId.setAttribute("src", changeId.getAttribute("src").replace(loadImg, exImg));
					var nextPos = stopPos+3;
					var changeImg = this.getAttribute("src").substring(startPos,nextPos)+"_big.jpg";
					changeId.setAttribute("src", changeId.getAttribute("src").replace(exImg, changeImg));
				}
			}
		}
	}
}

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