SetLineStyle procedure

  DECLARATION:  SetLineStyle(LineStyle : Word; Pattern : Word;
                             Thickness : Word);

      PURPOSE:  Set the current line width and style

         UNIT:  Graph

      REMARKS:  The values set by SetLineStyle affect all lines drawn by
                the graphics procedures: Line, LineTo, Rectangle, DrawPoly,
                Arc, etc.

                If invalid parameters are passed to SetLineStyle, GraphResult
                will return a value of -11 (grError), and the current
                settings will be left unchanged.

                The Graph unit declares these constants:

                                  Const
                                     SolidLn    = 0;
                                     DottedLn   = 1;
                                     CenterLn   = 2;
                                     DashedLn   = 3;
                                     UserBitLn  = 4;
                                     NormWidth  = 1;
                                     ThickWidth = 3;

 RESTRICTIONS:   Must first be in graphics mode.