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) {
		nav_home_over = newImage("images/nav_home_over.gif");
		nav_content_over = newImage("images/nav_content_over.gif")
		nav_register_over = newImage("images/nav_register_over.gif");
		nav_rtvphone_over = newImage("images/nav_rtvphone_over.gif");
		nav_rtvpc_over = newImage("images/nav_rtvpc_over.gif");
		nav_help_over = newImage("images/nav_help_over.gif");
		nav_redownload_over = newImage("images/nav_redownload_over.gif");
		nav_contact_over = newImage("images/nav_contact_over.gif");
		btn_yes_over = newImage("images/btn_yes_over.gif");
		btn_no_over = newImage("images/btn_no_over.gif");
		preloadFlag = true;
	}
}

function popWindow(fileName, popupName, height, width) { 
	window.open(fileName, popupName, 'width=' + width + ',height=' + height + ',scrollbars=no,resize=no,toolbar=no');
}