if (strcmp("/lock", cmdtext, true, 10) == 0)//your command. 
    { 
        new engine, lights, alarm, doors, bonnet, boot, objective; 
        new vehicleid = GetPlayerVehicleID(playerid);//defining vehicleid is = to GetPlayerVehicleID. 
        if(IsPlayerInAnyVehicle(playerid))//Thsi will check that is a player In a vehcile or not. 
            { 
                GetVehicleParamsEx(vehicleid,engine,lights,alarm,doors,bonnet,boot,objective);//will check that what is the state of the vehicle lock. 
                if(doors == 1)//will check if the doors are already loocked it not. 
                { 
                    GetVehicleParamsEx(vehicleid,engine,lights,alarm,doors,bonnet,boot,objective); 
                      SetVehicleParamsEx(vehicleid,engine,lights,alarm,false,bonnet,boot,objective);//same as the engine one. 
                      GameTextForPlayer(playerid,"Vehicle Unlocked!",2000,6);//for a text to appar on the screen for only 2 seconds. 
                       return 1; 
                } 
                else 
                SetVehicleParamsEx(vehicleid,engine,lights,alarm,true,bonnet,boot,objective); 
                GameTextForPlayer(playerid,"Vehicle Locked!",2000,6);//for a text to appar on the screen for only 2 seconds. 
            } 
            else 
            SendClientMessage(playerid,-1,"Error: You are not in a vehicle!");//the error message. 
    } 
    return 0; 
}

public OnPlayerEnterVehicle(playerid, vehicleid, ispassenger)
{
    return 1;
}

CMD:vlock(playerid, params[])
{
    new engine, vlights, alarm, doors, bonnet, boot, objective;
    new keycar = (dini_Int(PFile(playerid),"HaveCar"));
    new personalcar = (dini_Int(PFile(playerid),"CarID"));
    if(keycar == 0)return SendClientMessage(playerid, YELLOW, "You Don't Own A Vehicle To Unlock");
    if(!IsPlayerInAnyVehicle(playerid)) return SendClientMessage(playerid, YELLOW, "ERROR: You Are Not In A Vehicle");
    if(VehicleSystem[playerid][cLock] == 0)
    {
       GetVehicleParamsEx(personalcar,engine,vlights,alarm,doors,bonnet,boot,objective);
       SetVehicleParamsEx(personalcar,engine,vlights,alarm,true,bonnet,boot,objective);
       GameTextForPlayer(playerid,"~w~Vehicle ~g~Locked!",2000,6);
    }
    return 1;
}

CMD:vunlock(playerid, params[])
{
    new engine, vlights, alarm, doors, bonnet, boot, objective;
    new keycar = (dini_Int(PFile(playerid),"HaveCar"));
    new personalcar = (dini_Int(PFile(playerid),"CarID"));
    if(keycar == 0)return SendClientMessage(playerid, YELLOW, "You Don't Own A Vehicle To Unlock");
    if(!IsPlayerInAnyVehicle(playerid)) return SendClientMessage(playerid, YELLOW, "ERROR: You Are Not In A Vehicle");
    if(VehicleSystem[playerid][cLock] == 1)
    {
       GetVehicleParamsEx(personalcar,engine,vlights,alarm,doors,bonnet,boot,objective);
       SetVehicleParamsEx(personalcar,engine,vlights,alarm,false,bonnet,boot,objective);
       GameTextForPlayer(playerid,"~w~Vehicle ~g~Unlocked!",2000,6);
    }
    return 1;
}