CARD = OCONV(CARD,'MCN') TOTAL = 0 MULT = 2 FOR X = LEN(CARD)-1 TO 1 STEP -1 DIGIT = CARD[X,1] * MULT IF DIGIT GT 9 THEN DIGIT = DIGIT[1,1] + DIGIT[2,1] TOTAL += DIGIT MULT = 3 - MULT NEXT X
CHECK = MOD(10-MOD(TOTAL,10),10) IF CHECK NE CARD[1] THEN ! No match END Larry Hiscock Western Computer Services -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Baker Hughes Sent: Friday, December 02, 2005 8:11 AM To: [email protected] 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 [email protected] To unsubscribe please visit http://listserver.u2ug.org/ ------- u2-users mailing list [email protected] To unsubscribe please visit http://listserver.u2ug.org/
