Within Black ops 3 i'm trying to make a trigger just like this from the MWR shooting range. Trigger_multiple being activated when touched which starts an event, but can be canceled and reset at anytime during the event. I'm not a programmer so I've had a hard time reading random gsc files.
 

 
 
This is what I copied from some bo3 gsc files I read through which does activate only when I touch it, but i'm stumped on what to do when I leave the trigger. How do I know the player left it, and how would I stop a loop or function at anytime?
 

function detect_touched(trig)
{
    while ( true )
    {
        trig waittill( "trigger" );
        trig.script_touched = true;
        return;
    }
}

Incase you were wondering I only copied the function because I didn't know how to call it from another file.