Password Program

I am trying to write a password program that will accept to passwords: one to open a door, and another to gain full access to the computer. I know how to make the program and everything, but when I got to the part where it grants you full access to the computer I realized that I don't know how to do that. I couldn't think of any way to stop the program and just be a regular computer that you can use. I don't know if maybe it is involved in an API. I don't know if I am really explaining this very well so if you need me to try to explain it again please ask. Basically what I am asking is how to get out of a program and use the computer regularly.
Help is appreciated!
Thanks! :D/>

this code will exit a program from anywhere in the code

error()

if you are running in the program block using

return

will exit the program too.