In the same MFD as the flight mode buttons, there are two additional functions available: Programming the Joystick and Centering the Joystick. Just like the four buttons running along the bottom of the MFD, there are four buttons along the top. The left two buttons are used to program the joystick triggers, and the right two are to center the joystick and foot pedals.
To program the joystick, simply hit one of the two buttons above the "Program" area. Once one of these buttons has been toggled, they will start to flash and you will hear a warbling tone in the cockpit. Your are now in Program mode. At this point, you will need to push any one of the buttons in the MFDs. Once you push the button you want (say, "Booster"), hold it and look up to the Program/Flight mode MFD. In it, you will see a silhouette of a joystick with circles corresponding to triggers. If there are no buttons lit up in the silhouette, the function or trigger is not activated or not assigned to a trigger. If the circle is solid white, it means that there is only one weapon or function assigned to the trigger. If the circle has a white ring around a dark center, it means that two or more functions/weapons are assigned to that particular trigger on the joystick.
While holding the button down on the MFD, simply pull the trigger you want to assign the weapon or function to. You will now see the corresponding circle on the joystick silhouette light up. That particular weapon or function has now been assigned to the trigger. To de-assign, hold down the MFD button on the function or weapon, and pull the trigger where the function or weapon is located; the light will go out and the trigger will no longer activate that weapon or function.
To exit "Program" mode simply push one of the two buttons above the "Program" area. The flashing lights and sound will stop, and you can begin flying down the course.
The "Center" function allows the pilot to "zero" or center the cockpit's control inputs (joystick and foot pedals) should they become offset, or if you experience drift. To use this function, take your hands and feet off of the controls and hit the "Center" button once. Your controls are now re-centered and the VTV should fly the way you want it to.