>> Sorry no idea how to validate a credit card number ;-) >> > A good start to this is to check what the first digit is. > If it begins with a 4 it is a VISA card. If it begins with a 5 > it is a MasterCard. > That may be true in the USA but it isn't true in Australia. Here Mastercard start with 5 but Visa can start with 4 or 5 :-) Sarah