FUNCTION WritableDir(CONST Dir : STRING) : BOOLEAN;

  VAR

    FIL : FILE;

    N   : STRING;

    I   : Cardinal;

  BEGIN

    REPEAT

      N:=IncludeTrailingPathDelimiter(Dir);

      FOR I:= TO -LENGTH(N) DO N:=N+CHAR(RANDOM()+)

    UNTIL NOT FileExists(N);

    Result:=TRUE;

    TRY

      AssignFile(FIL,N);

      REWRITE(FIL,)

    EXCEPT

      Result:=FALSE

    END;

    IF Result THEN BEGIN

      CloseFile(FIL);

      ERASE(FIL)

    END

  END;