open(FILE, ">>$GUESTBOOK") or
      die "Can't open $GUESTBOOK: $!\n";
    flock(FILE, LOCK_EX); # Exclusive lock for writing

    print FILE $time, ':::', $name, ':::', $ip, ':::', $email, ':::', $comments, "\n";

    flock(FILE, LOCK_UN); # Unlock the file
    close FILE;