We have been using this Mod10 code for years. Note - CLEN = LEN(CARD.NUM) 0076 ** 0077 ** ================================================================ 0078 ** 0079 ALGO.CHECK: ** card number algorithm check 0080 CSTR = "" ; PTR = 0 0081 FOR I = CLEN TO 1 STEP -1 0082 PTR = PTR + 1 0083 IF MOD(PTR, 2) # 0 THEN MULTI = 1 ELSE MULTI = 2 0084 CSTR = CARD.NUM[I, 1] * MULTI : CSTR 0085 NEXT I 0086 ** 0087 CSUM = 0 ; CLEN = LEN(CSTR) 0088 FOR I = 1 TO CLEN 0089 CSUM += CSTR[I, 1] 0090 NEXT I 0091 ** 0092 IF NOT((MOD(CSUM, 10) = 0)) THEN 0093 ERR = "Invalid card number." 0094 END 0095 RETURN
Robin Stanley -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Baker Hughes Sent: Friday, December 02, 2005 8:11 AM To: u2-users@listserver.u2ug.org Subject: [U2] Mod10 Credit Card Checksum Say, has anyone written some code to validate a Credit Card number, using the Mod10 (nicknamed) or ANSI X4.13 (realname) LUHN formula? I was just told today get this installed yesterday, so I'm naturally looking to see if some kind-hearted fellow MV'ver has something already written (it is the season for giving ;-) ). I searched ansi.org and only got hits on meeting agendas - [in session 4.13 discuss blah blah] I found the previous u2ug posting that used Mod10 to validate a UPC, but it looks a bit different from algorithm described elsewhere to validate CCnumbers, and doesn't look agreeable to variable lengths (different you know based on each card type). I'm really thankful for U2UG, and glean much from the postings. I'd contribute more answers but I've only been at this 14 years and someone more seasoned invariably gives a thoroughly enlightening response. TIA. -Baker bakerdothughes atmouser dotcom ------- u2-users mailing list u2-users@listserver.u2ug.org To unsubscribe please visit http://listserver.u2ug.org/ ------- u2-users mailing list u2-users@listserver.u2ug.org To unsubscribe please visit http://listserver.u2ug.org/
