[Marricio]

pawn Код:

public OnPlayerEnterVehicle(playerid, vehicleid, ispassenger)
{
    if(vehicleid == bmx1 || vehicleid == bmx2 || vehicleid == bmx3)
    {
    if(postjob[playerid] == 0)
    {
    SendClientMessage(playerid, COLOR_DARKORANGE, "You need to start the post job /postjob");
    new Float:slx, Float:sly, Float:slz;
    GetPlayerPos(playerid, slx, sly, slz);
    SetPlayerPos(playerid, slx, sly, slz+1);
    }
    }
    return 1;
}

that should work