NAME: SetGraphMode

     USE: Sets the system to the specified graphic mode and clears the
          screen.  Prior to calling SetGraphMode, InitGraph must be
          called.  Errors are returned through GraphResult. Predefined
          constants are defined in the graph unit as parameters to
          SetGraphMode.


                       Graphics mode for each driver
         -----------------------------------------------------------

    CGA1       = 0; 320 X 200 color palette 1: red, yellow, green; 1 page
    CGA2       = 1; 320 X 200 color palette 2: cyan, magenta, white; 1 page
    CGAHi      = 2; 640 X 200 1 page
    MCGAC1     = 0; 320 X 200 color palette 1: red, yellow, green; 1 page
    MCGAC2     = 1; 320 X 200 color palette 2: cyan, magenta, white; 1 page
    MCGAMed    = 2; 640 X 200 1 page
    MCGAHi     = 3; 640 X 480 2 color, 2 pages
    EGALo      = 0; 640 X 200 4 pages
    EGAHi      = 1; 640 X 325 16 colors, 2 pages
    EGA64Lo    = 0; 640 X 200 16 colors, 1 page
    EGA64Hi    = 1; 640 X 315 4 colors, 1 page
    HercMonoHi = 3; 720 X 348 2 pages
    ATT400C1   = 0; 320 X 200 color palette 1: red, yellow, green; 1 page
    ATT400C2   = 1; 320 X 200 color palette 2: cyan, magenta, white; 1 page
    ATT400Med  = 2; 640 X 200 1 page
    ATT400Hi   = 3; 640 X 400 1 page
    VGALo      = 0; 640 X 200 16 colors, 4 pages
    VGAMed     = 1; 640 X 350 16 color, 2 pages
    VGAHi      = 2; 640 X 480 16 colors, 1 page
    VGAHi2     = 3; 640 X 480 2 colors, 1 page
    PC3270Hi   = 0; 720 X 350 1 page



     DEPENDENCY:  Must first be in graphics mode.  The unit Graph
                  must also be placed in the uses section.

     SYNTAX: SetGraphMode(ModeValue : Integer);