Simple Engine!

/****** INCLUDES *****/
#include <a_samp>
#include <zcmd>
/****** DEFINES *****/
new IsEngineOn[MAX_PLAYERS];
/****** STOCKS *****/
stock TurnEngineOn(playerid);
{
    new vehicleid = GetPlayerVehicleID(playerid), engine, lights, alarm, doors, bonnet, boot, objective;
    GetVehicleParamsEx(vehicleid, engine, lights, alarm, doors, bonnet, boot, objective);
    SetVehicleParamsEx(vehicleid, 1, lights, alarm, doors, bonnet, boot, objective);
    IsEngineOn[playerid] = 1;
}
stock TurnEngineOff(playerid);
{
    new vehicleid = GetPlayerVehicleID(playerid), engine, lights, alarm, doors, bonnet, boot, objective;
    GetVehicleParamsEx(vehicleid, engine, lights, alarm, doors, bonnet, boot, objective);
    SetVehicleParamsEx(vehicleid, 0, lights, alarm, doors, bonnet, boot, objective);
    IsEngineOn[playerid] = 0;
}
/****** COMMAND *****/
CMD:engine(playerid, params[])
{
    if(!IsPlayerInAnyVehicle(playerid)) return SendClientMessage(playerid, GREY, "You must be in a vehicle to use this command.");
    if(IsEngineOn[playerid] == 1)
    {
        TurnEngineOn(playerid);
    }
    else
    {
        TurnEngineOff(playerid);
    }
    return 1;
}