Bar3D procedure

  DECLARATION:  Bar3D(x1, y1, x2, y2 : Integer; Depth : Word; Top : Boolean)

      PURPOSE:  Draws a 3-D graphics bar using current fill style and color

         UNIT:  Graph

      REMARKS:  Draws a filled in 3-Dimensional bar using the patterns and
                colors defined by SetFillStyle or SetFillPattern. The outline
                is drawn in the current line style and the color set by
                SetLineStyle and SetColor.  If Top is TRUE a 3-D top is
                added to the Bar, else no top is added allowing stacking
                of two or more Bars.

 RESTRICTIONS:  Must be in graphics mode.

      EXAMPLE:  Uses Graph;

                Var
                   Gd, Gm : Integer;
                   y0, y1, y2, x1, x2 : Integer;

                Begin
                   Gd := Detect;
                   InitGraph(Gd, Gm, '');
                   If(GraphResult <> grOK) Then
                      Halt(1);
                   y0 := 10;
                   y1 := 60;
                   y2 := 110;
                   x1 := 10;
                   x2 := 50;
                   Bar3D(x1, y0, x2, y1, 10, TopOn);
                   Bar3D(x1, y1, x2, y2, 10, TopOff);
                   Readln;
                   CloseGraph;
                End.