Xampp 1.81, PHP 5.4.7

I got the warning for the previous section, when the user is not logged in.

I seem to have stopped the warning by adding this:
$country_info = $_SESSION['country_info'];
require(DIR_WS_CLASSES . 'order.php');$order = new order;//steve for PHP warning

$order->delivery = array('postcode' => $zip_code,
but this really needs to be addressed by the devs, I'm not informed enough to say this is a fix.