Dear bingjie2680, thanks for the great plugin!
It works perfectly and I like it very much. I have only one issue.
As you know, many WordPress themes (including default TwentyTwelve) have "no comments" message in comment.php, if there is no comments yet. Usually it wrapped in:
<p class="nocomments"> ... </p>
How can I make this message disappear after submitted comment?