Check out the quickstart...
http://www.gotdotnet.com/quickstart/aspplus/doc/webvalidation.aspx
This doesn't have exactly what you need, but I think it would get you
started on your own custom validator or regex validator.
> I need to code up the Luhn Mod 10 system or something similar to do
> credit card number validation before it is sent off to the server. I
> have some code but it is coded for VB and I need it to work with C# any
> information and/or help woudl be greatly appreciated..
>
> Morgan