title: Page rendered is empty even though view and controller exist.
body: <p>I'm following <a href="http://asciicasts.com/episodes/160-authlogic" rel="nofollow noreferrer">this article</a>(<a href="http://asciicasts.com/episodes/160-authlogic" rel="nofollow noreferrer">http://asciicasts.com/episodes/160-authlogic</a>), I'm not using nifty generator tho.</p>
  
  <p>I've done the User model and <code>localhost:3000/users/new</code> page works fine.</p>
  
  <p>But when I try to open <code>localhost:3000/login</code>, the page is just empty. The source is empty too.</p>
  
  <p>I've just copied the source from the site.</p>
  
  <p>routes.rb</p>
  
  <pre><code>map.login 'login', :controller =&gt; 'user_sessions', :action =&gt; 'new'
  map.logout 'logout', :controller =&gt; 'user_sessions', :action =&gt; 'destroy'
  map.resources :user_sessions
  map.resources :users
  </code></pre>
  
  <p>user_sessions_controller.rb</p>
  
  <pre><code>class UserSessionsController &lt; ApplicationController
    def new
      @user_session = UserSession.new
    end
  
    def create
      @user_session = UserSession.new(params[:user_session])
      if @user_session.save
        flash[:notice] = "Successfully logged in."
        redirect_to root_url
      else
        render :action =&gt; 'new'
      end
    end
  
    def destroy
      @user_session = UserSession.find
      @user_session.destroy
      flash[:notice] = "Successfully logged out."
      redirect_to root_url
    end
  end
  </code></pre>
  
  <p>/views/user_sessions/new.html.erb</p>
  
  <pre><code>&lt;% form_for @user_session do |f| %&gt;
    &lt;%= f.error_messages %&gt;
    &lt;p&gt;
      &lt;%= f.label :username %&gt;&lt;br /&gt;
      &lt;%= f.text_field :username %&gt;
    &lt;/p&gt;
    &lt;p&gt;
      &lt;%= f.label :password %&gt;&lt;br /&gt;
      &lt;%= f.password_field :password %&gt;
    &lt;/p&gt;
    &lt;p&gt;&lt;%= f.submit "Submit" %&gt;&lt;/p&gt;
  &lt;% end %&gt;
  </code></pre>
  
  <p>The code is just same as the site.</p>
  
  <p>The server console shows that the views are being rendered:</p>
  
  <blockquote>
    <p>Completed 200 OK in 149ms (Views: 145.5ms | ActiveRecord: 3.2ms)</p>
  </blockquote>
  
  <p>Why is the login form not displayed at all?</p>
  
  <p><strong>Update</strong></p>
  
  <p>After added new action 'index' into user_sessions controller(also plus index.html.erb), if I open <code>localhost:3000/user_sessions/index</code> shows me below message.</p>
  
  <blockquote>
    <p>Unknown action
    No action responded to show. Actions: create, destroy, index, and new</p>
  </blockquote>
  
  <p>And, this is WEBrick output</p>
  
  <blockquote>
    <p>Processing UserSessionsController#show
    (for 127.0.0.1 at 2010-01-22 12:47:10)
    [GET]</p>
    
    <p>Parameters: {"id"=>"index"}</p>
    
    <p>ActionController::UnknownAction (No
    action responded to show. Actions:
    create, destroy, index, and new):</p>
  </blockquote>