FillEllipse function

  DECLARATION:  FillEllipse(X, Y : integer; Xradius, Yradius : Word)

      PURPOSE:  Draws a filled ellipse

         UNIT:  Graph

      REMARKS:  Uses (X,Y) as a center point, and Xradius and Yradius
                as the horizontal and verticle axes.  The ellipse is filled
                with the current fill color and style, and bordered with the
                current color.

 RESTRICTIONS:  Must first be in graphics mode.