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) {
		button_01_over = newImage("http://www.driverseducation.ws/media/driver-education-2.jpg");
		button_02_over = newImage("http://www.driverseducation.ws/media/drivers-education-2.jpg");
		button_03_over = newImage("http://www.driverseducation.ws/media/defensive-driving-2.jpg");
		button_04_over = newImage("http://www.driverseducation.ws/media/contact-2.jpg");
		preloadFlag = true;
	}
}

function popupWindow(url) {
  window.open(url,'popupWindow','toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=yes,copyhistory=no,width=600,height=450,screenX=150,screenY=150,top=150,left=150')
}