authenticate payment pin only once

I need help, am working on project and am using card pin to authenticate payment. The problem is; I want this pin to be used only once. If it is tried again let it echo “SORRY THIS PIN HAVEN USED BEFORE, ACESS DENIED”
I know how to make is echo SUCCSESSFUL/WRONG if the pin is correct or wrong. Am just issue with using it just once.
Thanks. I tried posting my code for clarity but the textarea of this site declined it.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s