window.onload = chngDemo;
function chngDemo() {
	demoImg  = $$("#photo-retouch img");
	for(i = 0; i < demoImg.length; i++) {
		var demoObj = demoImg[i];
		demoObj.onmouseover = function() {
			thisSrc = this.getAttribute("src");
			newSrc = thisSrc.replace("b.jpg","a.jpg");
			this.setAttribute("src", newSrc);
		}
		demoObj.onmouseout = function() {
			thisSrc = this.getAttribute("src");
			newSrc = thisSrc.replace("a.jpg","b.jpg");
			this.setAttribute("src", newSrc);
		}
	}
}