Bug: enter a VISA number (example: the 4111 1111 1111 1111 test number), enter an expiration date, enter a 4 digit security code. An error appears: "enter a 3 or 4 digit security code". I entered 4 digits so the message is inappropriate. Probably it should be "enter a 3 digit security code", assuming that all VISA cards have 3 digit codes.