var aryImages = new Array(4);
var oldImage = null;

aryImages[0] = new Image();
aryImages[0].src = "images/menu/news_over.gif";
aryImages[1] = new Image();
aryImages[1].src = "images/menu/departments_over.gif";
aryImages[2] = new Image();
aryImages[2].src = "images/menu/about_over.gif";
aryImages[3] = new Image();
aryImages[3].src = "images/menu/work_over.gif";

function swap(src,imgIndex) {
	if (imgIndex > 0) imgIndex = imgIndex - 1;
	oldImage = document.images[src].src;
	if (oldImage.indexOf('_on.gif') > 0) return false;
	document.images[src].src = aryImages[imgIndex].src;
}

function swaprestore(src) {
	document.images[src].src = oldImage;
}