Ajax functionality seems to fail when on adding a div tag to my .js.erb file

I am doing some styling in my code where I want to display the time a message is posted on a groups forum in my app. Currently posting of every message in this forum works with AJAX functionality implemented via jQuery 1.4.

On including the div tag in my post_message.js.erb file, I find that the message doesn't post on the groups home page (the place where I have all the group specific discussions - a functionality similar to what one would get to see in FB groups).

The message gets saved in my DB and on refreshing the page I get to see the latest message posted.

The code in post_message.js.erb looks like this:

$("#new_post").before('<div id ="new_post"><%= escape_javascript(flash.delete(:notice)) %></div>');<!--TO-DO the flash messages aren't yet enabled/working-->
$("#latest_post").prepend("<%= @group_post.message %> by <%=  Investor.find(@group_post.post_by).first_name %>  <%=  distance_of_time_in_words(@group_post.created_at,Time.now) %> ago <br/><br/><hr/>");
$("#new_post")[0].reset();

The above code stops functioning properly when I change the second line to:-

$("#latest_post").prepend("<%= @group_post.message %> by <%=  Investor.find(@group_post.post_by).first_name %> <div class ="contentdispgrp"> <%=  distance_of_time_in_words(@group_post.created_at,Time.now) %> ago </div><br/><br/><hr/>");

The part of the code corresponding the above in _common.html.erb file (this is a partial view where I have all the html tags and id's which I am eventually using in my .js.erb file) looks like this:

<table>
<tr>

<%if @current_user.is_an_existing_member_of_group(@investor_group)%>
<%form_for  :group_post, @group_post, :url => {:action => :post_message, :id => params[:id]},:html => {:multipart => 'true', :id => 'new_post'} do |f| -%>
    Start Discussion:<br><%=f.text_field :message%>
   <!--<%=f.file_field :photo%> -->
   <%=submit_tag "Post"%></p>
  <%end%>

   <div id = "latest_post"> </div>


<%for a in @group_all_posts %>
<%= a.message %> by <%=  Investor.find(a.post_by).first_name %> <div class ="contentdispgrp" id="style_chck"> <%=  distance_of_time_in_words(a.created_at,Time.now) %> ago </div><br/><br/> <hr/>

        <%end%>


</tr>
<%end%>
</table>

My post_message method in my groups controller looks like this:

 def post_message 
      @investor_group = InvestorGroup.find(params[:id])
  

      unless @current_user.is_an_existing_member_of_group(@investor_group)
        flash[:notice] = "Please join this group to participate in discussions"
        redirect_to :action => :show, :id => @investor_group and return # try to find out what exactly does this command do with return stmnt
      else
        @group_post = GroupPost.new(params[:group_post])
      end
      #@group_post = GroupPost.new(params[:group_post])
     
      investor_id = session['investor_id']
      @group_post.investor_group_id = @investor_group.id
      @group_post.post_by = investor_id
      if @group_post.save
        flash[:notice] = 'Post was successfully created.'
       # redirect_to :action => :show, :id => params[:id] - removed after trying to implement ajax via jquery
      else
        flash[:notice] = 'Post was not successfully created.'
      end
      

      respond_to do |format|
        format.html {redirect_to :action => "show", :id => params[:id]}
        format.js
      end
     
  end
 

How can I fix this without refreshing the page? What am I doing wrong?

Edit

group.js file code:

jQuery.ajaxSetup({
    'beforeSend' : function(xhr) {
        xhr.setRequestHeader("Accept","text/javascript")
        }
})

$(document).ready(function(){
    $("#new_post").submit(function(){
        $.post($(this).attr("action"),$(this).serialize(),null,"script");
        return false;
    })
})

The bug was fixed by removing the extra quotes(") made use while defining the class wrt the stylesheet, there were already a pair of quotes with the prepend method.. in post_message.js.erb.