CMD:jump(playerid, params[])
{
    if(IsPlayerInAnyVehicle(playerid)) // we check if the player is in any vehicle
    {
        new vehid = GetPlayerVehicleID(playerid); // a variable to get player vehicle.
        new Float:X,Float:Y,Float:Z; // Floats to save cords
        GetVehicleVelocity(vehid,X,Y,Z); // We get cords and we store them in variable above.
        SetVehicleVelocity(vehid,X,Y,Z+0.3); // We put same expect Z+0.3 Which is higher
    }
    return 1;
}