Error Messages and Codes 
                                Graphic Errors 

    GraphResult will return a value that reports the status of the last
    call to a graphics routine.

  ERROR      GRAPHICS ERROR                   CORRESPONDING ERROR
  CODE         CONSTANT                          MESSAGE STRING
 ----------------------------------------------------------------------------

    0       grOK                   No Error
   -1       grNoInitGraph          BGI graphics not installed (use InitGraph)
   -2       grNotDetected          Graphics hardware not detected
   -3       grFileNotFound         Device driver not found
   -4       grInvalidDriver        Invalid device driver file
   -5       grNoLoadMem            Not enough memory to load driver
   -6       grNoScanMem            Out of memory to scan fill
   -7       grNoFloodMem           Out of memory in flood fill
   -8       grFontNotFound         Font file not found
   -9       grNoFontMem            Not enough memory to load font
  -10       grInvalidMode          Invalid graphic mode for selected driver
  -11       grError                Graphics Error
  -12       grIOerror              Graphics I/O Error
  -13       grInvalidFont          Invalid Font File
  -14       grInvalidFontNum       Invalid Font Number
  -15       grInvalidDeviceNum     Invalid Device Number