var ItemImg = Class.create();
ItemImg.prototype = {
	initialize : function(element) {
		this.element = $(element);
		src = this.element.src;
		srcOn = '';
		this.srcON = srcOn.concat(src.substring(0, src.length-4),'ON.png');
		this.srcOFF = src;
		heavyImage = new Image();
		heavyImage.src = this.srcON;
	},
	mouseover : function(){
		this.element.src = this.srcON;
	},
	mouseout : function(){
		this.element.src = this.srcOFF;
	}
}

Event.observe(window, "load", function() {
	$$(".itemimg").each(function(element) {
		var itemimg = new ItemImg(element);
		element.observe("mouseover", function() {
			itemimg.mouseover();
		});
		element.observe("mouseout",function() {
			itemimg.mouseout();
		});
	});
});