// JavaScript Document

/*
Standards Compliant Rollover Script (customized version)
Author of original script : Daniel Nolan
http://www.bleedingego.co.uk/webdev.php

img要素、input要素(type="image")にclass="imgover"というクラスをつければ、
src属性で指定したファイルのファイル名に_overを足した名前の画像を読み込んで表示してくれます。

*/

function initRollovers() {
	if (!document.getElementById) return

	var aPreLoad = new Array();
	var sTempSrc;	
	var targetTags = ["img", "input"];

	for(i = 0; i < targetTags.length; i++) {
		var aTargets = document.getElementsByTagName(targetTags[i]);
		
		for (var j = 0; j < aTargets.length; j++) {
			if (aTargets[j].className == 'imgover') {
				var src = aTargets[j].getAttribute('src');
				var ftype = src.substring(src.lastIndexOf('.'), src.length);
				var hsrc = src.replace(ftype, '_over'+ftype);

				aTargets[j].setAttribute('hsrc', hsrc);

				aPreLoad[j] = new Image();
				aPreLoad[j].src = hsrc;

				aTargets[j].onmouseover = function() {
					sTempSrc = this.getAttribute('src');
					this.setAttribute('src', this.getAttribute('hsrc'));
				}

				aTargets[j].onmouseout = aTargets[j].onclick = function() {
					if (!sTempSrc) sTempSrc = this.getAttribute('src').replace('_over'+ftype, ftype);
					this.setAttribute('src', sTempSrc);
				}
			}
		}
	}
}

window.onload = initRollovers;