RE: [PHP] Credit card number checker?

The check you want is called a MOD10 check. Most of the script libraries have sample code. I found sample codes there. However, when I needed it, I had to write it in ASP code. Here is the code that I use; IF AccountNoLength > 16 THEN ERRORState = "TRUE" ErrorMssg = "Account%20Number%20is%20too%20long.Please%20recheck%20and%20reenter." URL = "CCValidationFailed.asp?ErrorMSSG=" + ErrorMSSG Response.redirect URL END IF IF AccountNoLength < 13 THEN ERRORState = "TRUE" ErrorMssg = "Account%20Number%20is%20too%20short.Please%20recheck%20and%20reenter." URL = "CCValidationFailed.asp?ErrorMSSG=" + ErrorMSSG Response.redirect URL END IF IF AccountNoLength = 14 THEN ERRORState = "TRUE" ErrorMssg = "Account%20Number%20is%20incorrect%20.%20Incorrect%20Length." URL = "CCValidationFailed.asp?ErrorMSSG=" + ErrorMSSG Response.redirect URL END IF FOR x=1 TO LEN(AccountNo) ch=MID(AccountNo,LEN(AccountNo)-x+1,1) IF x mod 2=0 THEN sum=2*CINT(ch) qsum=qsum+(sum mod 10) IF sum>9 THEN qsum=qsum+1 END IF ELSE qsum=qsum+CINT(ch) END IF NEXT IF qsum mod 10<>0 THEN ERRORState = "TRUE" ErrorMssg = "Account%20Number%20is%20incorrect%20. Fails%20MOD10%20Check." URL = "CCValidationFailed.asp?ErrorMSSG=" + ErrorMSSG Response.redirect URL END IF Hope it helps. Jeff Pearson > -----Original Message----- > From: Dr. Evil [mailto:drevil@sidereal.kz] > Sent: Monday, July 16, 2001 3:12 PM > To: php-general@lists.php.net > Subject: [PHP] Credit card number checker? > > > > I know that credit cards have standard formats: There's a standard > number of digits, and whether the card is Visa, MC, Amex, etc is > encoded in the number, and there is some kind of checksum, and I think > the expiration is also encoded in the number. All of this is obvious > stuff that anyone designing such a system would do. > > I'm wondering if anyone can refer me to a site that describes what > this format is, so I can write some PHP code that will check to see if > a credit card number format is correct. I don't even want to try to > run the card through my merchant account if the format is obviously > wrong. I assume that banks check the rejection rate on their merchant > accounts, and too many bogus cards would not look good. > > I did a quick search on the web, and there are a vast number of > "hacker" credit card number generators, but that isn't exactly what > I'm looking for. > > Thanks > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, e-mail: php-general-unsubscribe@lists.php.net > For additional commands, e-mail: php-general-help@lists.php.net > To contact the list administrators, e-mail: php-list-admin@lists.php.net >