If you want to use NumPad8 then you should set on of your GTA sa controls to NumPad8.
I will show you how to do that script.
PHP код:
public OnPlayerKeyStateChange(playerid, newkeys, oldkeys)
{
if ((newkeys & KEY_NO) && !(oldkeys & KEY_NO))
{
if(IsPlayerInAnyVehicle(playerid) // checks if the player is in a vehicle
{
new engine, lights, alarm, doors, bonnet, boot, objective, vehicleid = GetPlayerVehicleID(playerid);
// we create some variables, these ones will store vehicle data. After we get the id of the vehicle
GetVehicleParamsEx(vehicleid, engine, lights, alarm, doors, bonnet, boot, objective); //we store vehicles data inside the variables we created
if(engine == 0) engine = 1; //if: the engine is off we turn it on
else if(engine == 1) engine = 0; // viceversa
SetVehicleParamsEx(vehicleid, engine, lights, alarm, doors, bonnet, boot, objective); we update vehicles data
}
}
return 1;
}