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checking for information

I use ASP to check users data they submit. In particular, I'm checking for
credit cards and I also use a server component DynuCreditCard. It basically
affirms that the number "could be" a real credit card number.

Anyway, I cannot get through the website without having a legit CC#. None of
the handful of testers that help cannot get through without a legit CC#.
About once a month some user gets through with a blank credit card field.
How do you troubleshoot something like that? I can't replicate the problem.
Do you just say... "oh well... there was a computer glitch"...? How can I
approach this problem?

thanks
Jul 19 '05 #1
2 1434
Check the length of the data before passing it to the control.

strCardID = Trim(strCardID)
If Len(strCardID ) > 1 Then
'Send To Whatever
End If
dlbjr

Unambit from meager knowledge of inane others,
engender uncharted sagacity.
Jul 19 '05 #2
In article <#Q**************@tk2msftngp13.phx.gbl>,
sh***@tampabay.rr.com says...
Anyway, I cannot get through the website without having a legit CC#. None of
the handful of testers that help cannot get through without a legit CC#.
About once a month some user gets through with a blank credit card field.
One of the hardest things to account for in ASP programming is the back
button. Users will do the darndest things. Try running your program
and going forward and back at crucial points...

I use ASP to check users data they submit. In particular, I'm checking for
credit cards and I also use a server component DynuCreditCard. It basically
affirms that the number "could be" a real credit card number.


By the way, that's called a "Luhn Checksum" and although I don't have
the code specs handy, I've programmed it in both C and perl. It's only
about six lines of code. Personally, instead of loading a server
component for six lines of code (Did you *pay* for this control?) I'd do
a web search on Luhn checksum and find some sample code to adapt.

It's ok for checking for typos, but any respectable hacker will have a
utility that generates CC numbers with a valid Luhn checksum. If it
comes right down to it, the checksum is just the last number. All you
have to do is try all 10 digits until you hit one that works.

-- Rick
Jul 19 '05 #3

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