Saitek X45 and MS Flight Sim 98

Hi All. Having some trouble here. I am a new user to flight sims and hope to be an expert in a couple of years. Initailly, I have gone out a purchased a Saitek X45 joystick, as I researched the market and thought that it was a good buy. I am very happy with it. I have since purchased MS FS 98 as I thought it was best to start at the beginning and see what it was like. I look forward to purchasing MS FS 2004 Century of Flight in a couple of months. Anyway, my question is, "How do I get the Throttle/rudder working in the game." Win XP reconises the joystick and it is calibrated correcttly. No problems there. But when I start the Sim and begin to increase Throttle, nothing happens. I went into the options screen and tried to assign the feature, but all I get is a blank square/rectangle(meaning that nothing assisned.) Am I missing something? Look forward to your here for a new beginner. Cheers from Australia....Craig