Destroy a mission?

[salmo]

OK, I'm dumb I can't figure out how to destroy/unload an entire mission using the mission number. Here's what I have:

int i = GamePlay.gpNextMissionNumber();
GamePlay.gpPostMissionLoad("missions/Multi/Dogfight/aus3/misc/my_mission.mis");
sendScreenMessageTo(1, "my_mission loaded", null);
Timeout(5 * 60, () =>      // wait 5 min
{
// destroy my_mission here using mission number i
}
);