Navbar Collapse not working, Twitter Bootstrap

Question

Twitter bootstrap collapse is not working, once I decrease the screen size, it collapses to the smaller version, but when I click on button to show the drop down, its not working. Dont know whats wrong.

<div class="navbar navbar-inverse">
  <!-- Wrap the .navbar in .container to center it within the absolutely positioned parent. -->
  <div class="container">
    <div class="navbar navbar-static-top">
      <div class="navbar-inner">
        <div class="container-fluid">
          <a class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
          </a>
          <a class="brand" href="#"><%= image_tag("logowhite.png", :size => "27x27", :id => "logo") %></a>
          <div class="nav-collapse collapse navbar-responsive-collapse" id="paddy9">
            <p class="navbar-text pull-right">
              <% if user_signed_in? %>
                  <%= current_user.FirstName %> <%= current_user.LastName %> |
                  <%= link_to "Sign Out", destroy_user_session_path,:method => :delete,:style=>'color:#FFFFFF;', :class => "css_class"%>
              <% else %>
                  <%= link_to "Sign In", new_user_session_path, {:style=>'color:#FFFFFF;', :class => "css_class"} %>
                  | <%= link_to "Sign Up", new_user_registration_path, {:style=>'color:#FFFFFF;', :class => "css_class"} %>
                  or Join Using
                  <%= link_to image_tag("faceb.png", :size => "32x32"), user_omniauth_authorize_path(:facebook) %>
                  <%= link_to image_tag("twit.png", :size => "32x32"), user_omniauth_authorize_path(:twitter) %>
                  <%= link_to image_tag("g1.png", :size => "32x32", :class=> "img-rounded"), user_omniauth_authorize_path(:google_oauth2) %>
              <% end %>
            </p>
            <ul class="nav">
              <li class="active" id="paddy2"><%= link_to "Home", root_path,{:style=>'color:#FFFFFF;', :class => "css_class"} %></li>
              <% if user_signed_in? %>
                  <% if current_user.Company.nil? %>
                      <% if current_user.profile_id == nil %>
                          <!--   <li><%= link_to "Create Profile", new_profile_path %></li>  -->
                      <% else %>
                          <!--    <li><%= link_to "My Profile", profile_path(current_user.profile_id) %></li> -->
                      <% end %>
                  <% end %>
                  <% if current_user.Company.nil? %>
                      <!-- <li><%= link_to "Investment Portfolio", estates_path %></li> -->
                      <!-- <li><%= link_to "Social Network", '#' %></li> -->
                  <% else %>
                      <li class="paddy1"><%= link_to "Clients", management_index_path,{:style=>'color:#FFFFFF;', :class => "css_class"} %></li>
                  <% end %>
                  <li class="paddy1"><%= link_to "Account Settings", edit_user_registration_path,{:style=>'color:#FFFFFF;', :class => "css_class"} %></li>
              <% end %>
              <% unless user_signed_in? %>
              <li class="paddy1"><%= link_to "What is Mazzey?", home_what_path,{:style=>'color:#FFFFFF;', :class => "css_class"} %></li>
              <li class="paddy1"><%= link_to "Who it's for.", home_who_path,{:style=>'color:#FFFFFF;', :class => "css_class"} %></li>
              <li class="paddy1"><%= link_to "How it works.", home_how_path,{:style=>'color:#FFFFFF;', :class => "css_class"} %></li>
                  <% end %>


              <!-- <li><%= link_to "FAQs", faq_faqs_path %></li> -->
            </ul>
          </div><!--/.nav-collapse -->
        </div>
      </div>
    </div>
  </div>
</div>

Answer 1

downloaded and added bootstrap-collapse.js separately

   <%= javascript_include_tag "bootstrap-collapse.js" %>