Joystick Controls Help!?

I downloaded FlightGear for my Mac, and I am using the Logitech Wingman Extreme joystick for it, and in the game it wants me to turn my joystick left and right for thrust. Normally, I would use the slider for thrust, and it isn't really possible to fly the plane by turning the joystick left and right to thrust. On their website, they say to change the controls for the game I would have to program something into the game or something like that, and I can not do that. I just don't know how. So, how could I change my joysticks controls? I would greatly appreciate any help. Thank you for all of your answers.