loyalty: Source: Luhn Algorithm(Check for valid Credit Card Numbers)

A few days back a guy on HF posted an app that checks if the given no is a valid credit card no. or not, the app on the back end was using a websites which was using Luhn Algorithm to check whether the no. is a valid credit card no. or not but hey who'll trust a website for a credit card no. so here is an implementation of Luhn Algorithm in vb.net to check if the cc no. is valid or not :)