gBox()

         Draws a box in graphic mode

    Syntax:

         gBox ( nX1, nY1, nX2, nY2, nColor ) -> Nil

         nX1    : Initial coordinate X
         nY1    : Initial coordinate Y
         nX2    : Final coordinate X
         nY2    : Final coordinate Y
         nColor : Numeric value color

    Description:

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

    Return:

         Nothing.

    Example:

         gBox ( 200, 300, 250, 350, 4 )