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];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		home_over = newImage("images/btnHome-Over.jpg");
		aboutus_over = newImage("images/btnAboutUs-Over.jpg");
		technical_over = newImage("images/btnTechnical-Over.jpg");
		management_over = newImage("images/btnManagement-Over.jpg");
		operations_over = newImage("images/btnOperations-Over.jpg");
		links_over = newImage("images/btnLinks-Over.jpg");
		contactus_over = newImage("images/btnContactUs-Over.jpg");
		preloadFlag = true;
	}
}