window.onload = function() {
	RollOver();
	SetActiv();
};

function RollOver() {
	var conf = {
		className : 'Hov',
		postfix : '_hov'
	};
	var imgNodeList = getElementsByClassName(conf.className);
	var node;
	for (var i=0, len=imgNodeList.length; i<len; i++) {
		node = imgNodeList[i];
		node.originalSrc = node.src;
		node.rolloverSrc = node.originalSrc.replace(/(\.gif|\.jpg|\.png)/, conf.postfix+"$1");
		preloadImage(node.rolloverSrc);
		node.onmouseover = function() {
			this.src = this.rolloverSrc;
		};
		node.onmouseout = function() {
			this.src = this.originalSrc;
		};
	}
}

function SetActiv() {
	var conf = {
		className : 'On',
		postfix : '_hov'
	};
	var imgNodeList = getElementsByClassName(conf.className);
	var node;
	for (var i=0, len=imgNodeList.length; i<len; i++) {
	node = imgNodeList[i];
	node.src = node.src.replace(/(\.gif|\.jpg|\.png)/, conf.postfix+"$1");
	}
}


function getElementsByClassName(name){
	var elements = [];
	var allElements = document.getElementsByTagName('*');
	for (var i=0, len=allElements.length; i<len; i++) {
		if (allElements[i].className == name){
			elements.push(allElements[i]);
		}
	}
	return elements;
}

preloadedImages = [];
function preloadImage(url){
	var p = preloadedImages;
	var l = p.length;
	p[l] = new Image();
	p[l].src = url;
}