Joystick Interface:
  Overview        About these routines
  XPjoy1()        Return the status of the 1st joystick button (1 or 2)      .
  XPjoy2()        Return the status of the 2nd joystick button (1 or 2)      .
  XPjoyX()        Return the X coordinate of the Joystick
  XPjoyY()        Return the Y coordinate of the Joystick