[Kwarde]

Ehm, and what should it do? Check if the player is in any zone, or if the player's in gangzone 'id'. For the first one, there is no function yet, but it's easy to make. For the second one: IsPlayerInArea(playerid, areaid);. And now 'bout the first one:

pawn Код:

stock IsPlayerInAnyZone(playerid)
{
    for(new i = 0; i < MAX_AREAS; i++)
    {
        if(!AreaInfo[i][aCreated]) continue; //Better perfomance, mostly
        if(IsPlayerInArea(playerid, i) return true;
        continue;
    }
    return false;
}

If you want something else with it, please say it. And why a callback by the way?