Haha no point mate, your no idiot. I've just played this too long.
Heres a mockup example mission that I created in notepad, so forgive me if the mission doesn't work, but I'm guessing the script layouts will.
If the mission doesn't work, just note that the box in question executes from the init line like so:
nul = this spawn compile preprocessfile "ammobox_1.sqf"
You may also want to add in your ammo_box script to it, I have provided one for you.