Int 21 Fn 3E  - DOS 2+ - "close" - Close File                              [D]

   AH = 3Eh
   BX = file handle

Return: CF clear if successful
       AX destroyed
   CF set on error
       AX = error code (06h) (see AH=59h)

Note:  if the file was written to, any pending disk writes are performed, the
     time and date stamps are set to the current time, and the directory
     entry is updated

See Also: AH=10h,AH=3Ch,AH=3Dh,INT 2F/AX=1106h,INT 2F/AX=1227h