[PHP] Modulo eleven function?

Is anyone of you aware of a modulo eleven function that is used to calculate the checksum of a creditcard number? I have a pretty crude code listing from a book, but what I look for is a function that can append the checksum digit to a number. I have the spec for the algorithm behind the

RE: [PHP] Modulo eleven function?

Hi Børge, Is anyone of you aware of a modulo eleven function that is used to calculate the checksum of a creditcard number? I'm aware of the mod-10 algorithm (also known as the Luhn algorithm) - is that what you were after? There's a class that does this, amongst other things, at