Triggers not working with scripts

[Punch_145]

Cant seem to get it to work...........
I have a trigger set for some Dorniers to spawn. The trigger is a air group entering an area and I see the Hud message but no dorniers spawn?

public override void OnTrigger(int missionNumber, string shortName, bool active)
    {
        base.OnTrigger(missionNumber, shortName, active);

        if ("DoSpawn".Equals(shortName) && active)
        {
            AiAction action = GamePlay.gpGetAction("DoSpawn");

            if (action != null)
            {
                action.Do();
            }
            SendScreenMessageTo(Blue(), "Dorniers request Escort: Boulogne,(H,5) Alt:3500M, 10 mins ! ");
            GamePlay.gpGetTrigger(shortName).Enable = false;

        }
}