Title: Using programs to allow some features to work?

So I had made a simple lock program, i watched a tutorial on youtube and did the EXACT same, but when i tried to run it, it would error saying "startup:5: attempt to call nil", I looked around and it said it's because the code I was trying to run was not installed into my perihpals or ip? and it said I should make a program to utilise the features, I am completely unsure now of what I am supposed to do? help

I'm not exactly sure what you mean. Can you post the code that's getting the error?

please post your code, it will help us help you

EDIT: Ninja <_</>