/*
    Put at end of graphics drawing in loop
    note: you dont need to "erase" the things on the screen
    to return to normal drawing mode use:
    setvisualpage(1);
    setactivepage(1);

    */

    void UpdateDisplay()
    {
      if (getactivepage() == 1)
      {
        setvisualpage(1);
        setactivepage(2);
      }
      else
      {
        setvisualpage(2);
        setactivepage(1);
      }
      cleardevice();
    }