Can't wrap my head around this...

I'm trying to build a pin protected storage container for users on my server, and I'm using this as a starting point The goal is to make it so that a public user can set and enter a code (via permission blocks), but only a faction member can reset the system.

The problem I'm having is, I need a way to disable the program button once someone has set a code the first time. I've...

Can't wrap my head around this...