Credit card validator

Hello, does anyone know how to check validity of credit card using php code?
If you know, please tell me, thanks a lot!

please tell me,check validity of credit card thanks a lot!

regard
tom

Hello,

Please visit following url, it may help you

fyi,

to test your validator, you'll need fake creditcard accounts with valid numbers, I found these in a java book.

visa - 4111 1111 1111 1111
mastercard - 5555 5555 5555 4444
amex - 378282246310005
discover - 6011 1111 1111 1117

lee