Ajax action won't reflect on appearance but the value. Why? - ruby-on-rails

Question

I'm using Rails3. Now trying to implement follow button in index.html.erb just like twitter.
It shows member list and their follow buttons.
It looks okay but if I press any of those follow button, appearance doesn't change.
It should changes follow to un-follow right away.
I have no idea why it does. But if I reload the page, it shows correct status.
follows_controller.rb
class FollowsController < ApplicationController
def create
#user = User.find(params[:user_id])
current_user.follow(#user)
respond_to do |format|
format.js {render :action=>"create.js"}
end
end
def destroy
#user = User.find(params[:user_id])
current_user.stop_following(#user)
respond_to do |format|
format.js {render :action=>"destroy.js"}
end
end
end
views/users/_follow_user.html.erb
<% unless user == current_user %>
<% if current_user.following?(user) %>
<%= button_to("Un-Follow", user_follow_path(user.to_param, current_user.get_follow(user).id),
:method => :delete,
:remote => true,
:class => 'btn') %>
<% else %>
<%= button_to("Follow", user_follows_path(user.to_param),
:remote => true,
:class => 'btn btn-primary') %>
<% end %>
<% end %>
views/users/create.js.erb
$('.follow_user[data-user-id="<%=#user.id%>"]').html('<%= escape_javascript(render :partial => "follow_user", :locals => {:user => #user}) %>');
#jQuery
views/users/destroy.js.erb
$('.follow_user[data-user-id="<%=#user.id%>"]').html('<%= escape_javascript(render :partial => "follow_user", :locals => {:user => #user}) %>');
#jQuery
views/users/index.html.erb
<%- model_class = User.new.class -%>
<div class="page-header">
<h1><%=t '.title', :default => model_class.model_name.human.pluralize %></h1>
</div>
<% #from %>
<h3>tag cloud</h3>
<% tag_cloud(#tags, %w(css1 css2 css3 css4)) do |tag, css_class| %>
<%= link_to tag.name, {:action=>'index', :tag=>tag.name}, :class => css_class%>
<% end %>
<%= paginate #users %>
<table class="table table-condensed">
<thead></thead>
<tbody>
<% #users.each do |user| %>
<div class="memberListBox">
<div class="memberList">
<p class="name"><span><%= user.user_profile.nickname %></span>(<%= user.user_profile.age %>)</p>
<p class="size"><%= user.username %></p>
<p class="img">
<% if user.user_profile.user_avatar? %>
<%= image_tag(user.user_profile.user_avatar.url(:thumb),:height => 100, :width => 100, :class => 'img-polaroid' ) %>
<% else %>
<%= image_tag('nophoto.gif',:height => 100, :width => 100, :class => 'img-polaroid' ) %>
<% end %>
</p>
<div class="introduction">
<%= user.user_profile.introduction %>
</div>
<% if user_signed_in? && current_user!=user %>
<div id="follow_user">
<%= render :partial => "follow_user", :locals => {:user => user} %>
</div>
<% end %>
<%= link_to sanitize('<i class="icon-pencil icon-white"></i> ') + 'Message', new_messages_path(user.username), :class => 'btn btn-primary' %>
<%= link_to sanitize('<i class="icon-user icon-white"></i> ') + 'Profile', show_user_path(:username => user.username, :breadcrumb => #from), :class => 'btn btn-info' %>
</div>
</div>
<% end %>
</tbody>
</table>
response content
$('#follow_user').html(' <form action=\"/users/1/follows\" class=\"button_to\" data-remote=\"true\" method=\"post\"><div><input class=\"btn btn-primary\" type=\"submit\" value=\"Follow\" /><input name=\"authenticity_token\" type=\"hidden\" value=\"G/taOUeWy2gumhWUi10cPvECAmYLQdhQ2/eGGMJwvPE=\" /><\/div><\/form>\n');

Answer 1

Add the user id to the attribute data-user-id and add the class follow_user
<div class="follow_user" data-user-id="<%= user.id %>">
<%= render :partial => "follow_user", :locals => {:user => user} %>
</div>