IO-error description:
  If in a directory-list of different file-types you select
  unfortunately a text-file, then this text-file will be opened.
  After this mistake if you again try to use the IO-functions REWRITE, RESET
  for untyped files, each time a IOResult-error is reported.
  You have to exit to DOS and restart the program for error-correction.

  Is there a possibility for correction without exit the programm?
  }
  PROCEDURE DataStore_OldFile( VAR name   :  PathStr;
                               VAR d      : FILE;
                               VAR err_nr : Err_Typ);
    VAR
      f : FILE;     {untyped}
      io_Result : INTEGER;
  BEGIN
    {$IFOPT I+} {$DEFINE IPLUS} {$I-} {$ENDIF }
    ASSIGN( f, name);
    RESET(  f, 1);           { Blocksize 1}
    io_result := IOResult;
    IF io_result = 0 THEN
    BEGIN
       ....
      d := f;
    END ELSE
    BEGIN
      {ERROR-MESSAGE}
      err_nr := io_result;
      d := NIL;
    END;
    CLOSE( f);
    io_result := IOResult;
    {$IFDEF IPLUS} {$UNDEF IPLUS} {$I+} {$ENDIF}
  END;