Problem: The program can accept an old Visa card with 13 digits. which should already be replaced by 16 digits nowadays. Steps to reproduce: 1. Go to check out after picking the seat. 2. Enter the credit card number and security code 3. Press submits and confirm the selection Expected Result: An error message should be displayed. Actual Result: The program display and confirm message. After my acceptance, the system passed and processed my request.