Setting values

How do I set a value to an item? I've been checking a couple of the script files but I can't make any sense of it.

What I want is one thing to happen when a certain trigger is triggered, but not again if the trigger is called later, unless a second trigger has been triggered between. I figured (from experience in other languages) the easiest way would be to set a value to 1 the first time is triggered, then setting it to 0 again when the second trigger is ran, and making my little piece of code only run when the value is 0.

Anyone got any ideas?


Side question: In the sound cfg files, there's a number on the line after the wav file location. What is this, and also can I have several origins of a sound, and is there any way to make the sound only audible from inside the bus (unless the doors are open)?