Graphics-Mode Error Codes and Message Strings

 Error
 Code    Error Constant     Error Message String
  0      grOk               No error
  1      grNoInitGraph      BGI graphics not installed
  2      grNotDetected      Graphics hardware not detected
  3      grFileNotFound     Device driver file not found
  4      grInvalidDriver    Invalid device driver file
  5      grNoLoadMem        Not enough memory to load driver
  6      grNoScanMem        Out of memory in 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 graphics mode for selected driver
 11      grError            Graphics error  (generic error)
 12      grIOerror          Graphics I/O error
 13      grInvalidFont      Invalid font file
 14      grInvalidFontNum   Invalid font number