Files to be altered:
catalog/includes/modules/payment/psigate_xml.php
catalog/includes/languages/english/payment/psigate_xml.php

***Note - the javascript function and the decline error message are
necessary changes, the others are preferences.

Alterations:
1. Added an email title for the payment method so it says
Payment Method: Credit Card, instead of PSI Gate XML on the confirmation email.

2. Updated the previously submitted js validation script, just needed ''s in front of the n's

3. Added the display of Card Type on the checkout confirmation page.

4. Changed display of CC Number on checkout confirmation page to only show last 4 digits.

5. Fixed the Declined Credit Card code in the before_process function - was previously not
displaying the error on the page, only redirecting them to the payment page without feedback.

More...