User interface appears when staged missions are run
a. A pop-up appears in your current window to opt-ito stage mission (but only if you're not flying/driving/gunning etc as with current mission system)
b. If you select opt-out, you return to what ever you were doing. You can only select opt-in however if you're not in craft however.
c. If you select opt-in, a list of current pilot positions appear, and you select the current assignment you wish to fly.
d. You then appear in briefing room.
