(* exists checks to if fileName exists.
   Parameters: fileName : String - The file to be checked
   Return value : boolean - True if it exists,
   otherwise, false. *)
FUNCTION exists(fileName: String) : Boolean;
VAR
dummyFile : textfile;
BEGIN { exists }
  {$I-} { turn off error messages }
  assign(dummyFile, fileName); { assign name to system file }
  reset(dummyFile); { try to open for input }
  close(dummyFile); { close dummy file }
  {$I+} { turn on error message }
  exists := IOResult = 0; { call IOResult function to see if o.k. }
END; { exists }