gCircle()

         Draws a circle in graphic mode

    Syntax:

         gCircle ( nCenterX, nCenterY, nRadius, nColor ) -> Nil

         nCenterX : Coordinate X of center
         nCenterY : Coordinate Y of center
         nRadius  : Radius value
         nColor   : Numeric value colour

    Description:

         It draws a circle in graphic mode. The mode must be EGA or VGA.

    Return:

         Nothing.

    Example:

         gCircle ( 200, 300, 50, 2 )