function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

function preloadImages() {
	if (document.images) {
		btnOver01 = newImage("images/btn-home-over.gif");
		btnOver02 = newImage("images/btn-about-over.gif");
		btnOver03 = newImage("images/btn-sigsigrho-over.gif");
		btnOver04 = newImage("images/btn-news-over.gif");
		btnOver05 = newImage("images/btn-expansion-over.gif");
		btnOver06 = newImage("images/btn-contact-over.gif");
		btnOver07 = newImage("images/btn-guestbook-over.gif");
		btnOver08 = newImage("images/btn-qayamat-over.gif");
		preloadFlag = true;
	}
}