Graph  Unit 
                               Bar3D Constants 

      PURPOSE:  Constants use to control the effects of Bar3D

      REMARKS:  Use these constants with Bar3D to specify whether a 3D top
                should be drawn on the Bar.  When TRUE, a top is drawn onto
                the Bar, else it is drawn without a top.  This allows you to
                draw multiple, stacked Bars and place a top only on the
                topmost Bar.  The constants are declared as:

                            Const
                               TopOn  = TRUE;
                               TopOff = FALSE;