[antonio112]

Try it this way:

pawn Код:

CMD:quitjob(playerid,params[])
{
    if(PlayerInfo[playerid][pJob] == 0)
        return SendClientMessage(playerid, COLOR_GREY, "You do not have a job!");

    SendClientMessage(playerid, COLOR_WHITE, "You have quit a job!");
    PlayerInfo[playerid][pJob] = 0;
    PlayerInfo[playerid][pChar] = 0;
    PlayerInfo[playerid][pContractTime] = 0;
    SetPlayerToTeamColor(playerid);
    return 1;
}

You don't have to check if the player who types the command is connected. It makes no sense at all.