How to validate credit cards Numbers in access textbox

[Dan1]

Hi Guys,
I have borrowed below VB code which I like to use to validate card numbers in ms access 2003 Database text box"CardNumber " The card will be checked as the user clicks a command buttom and the card number saved if valid.
I will greatly appreciate it if this forum can help me out.I guess the code I have to paste the code in a module and call it up some how. I am new to access so a step by step guide will be great.
Thanks

** Edit **
Code replaced by link as the code is explicitly copyrighted and does NOT allow for posting the code elsewhere (IE here).
** Edit **

' COPYRIGHT NOTICE:
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[NeoPa]

Dan,
I'm afraid that even if it were ok to include the code you want help with, we are not simply a free resource to do your work for you.
We answer specific questions where we can and look to help people understand the subject better where that is possible.
We normally look for directing members who explain what they're trying to do and where they've got stuck. Simply posting an enormous chunk of code and asking us to get it working for you is not acceptable. The fact that it's somebody else's too and you've done nothing with it so far merely adds insult to injury. If you're prepared to ask specific questions then we can help, but otherwise this is not the place for you to find what you want.

ADMINISTRATOR.