How to show jquery ajax data correctly when it include in a php mysql query?

I want to add a comment system after my article, <form id="postform" class="postform"> is written into a MYSQL_QUERY result circle. but after post a comment, the current posted comment will be showed in all the <div class="post_comment"></div>, how to modify jquery ajax part so that the current posted comment only be showed in its own <div class="post_comment"></div>? thanks.

jquery ajax part

$(document).ready(function(){
$(".Submit").click(function(){
var title    = $(this).closest('form').find("#title").val();
var content   = $(this).closest('form').find("#content").val();
$.ajax({
type: "POST",
url: "ajax_post.php",
data: {title:title,content:content},
success: function(date_added){
if(date_added != 0)
{
var structure = '<div class="comment_date_added">'+date_added+'</div><div class="comment_content">'+content+'</div>';        
$(".post_comment").prepend(structure);
}
}
});
});
});

Code (markup):

PHP part

<?php
...
while($result = mysql_fetch_array($resultset))
{
$article_title = $result['article_title'];
...
?>
<form id="postform" class="postform">
<input type="hidden" name="title" id="title" value="<?=$article_title;?>" />
<input type="text" name="content" id="content" />
<input type="button" value="Submit" class="Submit" />
</form>
<div class="post_comment">
<?php
$resultSet = @mysql_query("select * from customcomment where article='".$article_title."' order by date_added desc");
while($resultRow = mysql_fetch_array($resultSet))
{
$date_added = $resultRow['date_added'];
$comment = stripslashes($resultRow['content']);
?>
<div class="comment_date_added"><?=$date_added;?></div><div class="comment_content"><?=$comment;?></div>
<?php
}
?>
</div>
...
<?php
}
?>

Code (markup):

 

I am sorry, I can not open in opera 10, so I think the link is broken. I posted 2 question repeat.