[<Weponz>]

Have a area where they can leave and goto other arenas,Use that position for the /exit and use IsPlayerInArena == true; under the arena commands(teleports) and when they /exit use IsPlayerInArena == false etc etc to determine if they have used the arena command yet then u can just use else SendClientMessage, 0x0, "Your not in any arenas to exit!");

Use

new bool IsPlayerInArena[MAX_PLAYERS];

Should work

Hope it helps