login OK

app/assets/javascripts/application.js

-// This is a manifest file that'll be compiled into application.js, which will include all the files
-// listed below.
-//
-// Any JavaScript/Coffee file within this directory, lib/assets/javascripts, vendor/assets/javascripts,
-// or vendor/assets/javascripts of plugins, if any, can be referenced here using a relative path.
-//
-// It's not advisable to add code directly here, but if you do, it'll appear at the bottom of the
-// compiled file.
-//
-// Read Sprockets README (https://github.com/sstephenson/sprockets#sprockets-directives) for details
-// about supported directives.
-//
 //= require jquery
 //= require jquery
 //= require jquery_ujs
 //= require jquery_ujs
+//= require bootstrap
 //= require turbolinks
 //= require turbolinks
 //= require_tree .
 //= require_tree .

app/controllers/application_controller.rb

@@ -2,4 +2,5 @@ class ApplicationController < ActionController::Base
   # Prevent CSRF attacks by raising an exception.
   # Prevent CSRF attacks by raising an exception.
   # For APIs, you may want to use :null_session instead.
   # For APIs, you may want to use :null_session instead.
   protect_from_forgery with: :exception
   protect_from_forgery with: :exception
+	include SessionsHelper
 end
 end

app/views/layouts/_header.html.erb

@@ -5,8 +5,23 @@
           <ul class="nav navbar-nav pull-right">
           <ul class="nav navbar-nav pull-right">
             <li><%= link_to "Home",   root_path %></li>
             <li><%= link_to "Home",   root_path %></li>
             <li><%= link_to "Help",   help_path %></li>
             <li><%= link_to "Help",   help_path %></li>
-            <li><%= link_to "Log in", '#' %></li>
+						<% if logged_in? %>
+							<li><%= link_to "Users", "#" %></li>
+							<li class="dropdown">
+								<a href="#" class="dropdown-toggle" data-toggle="dropdown">
+									Account <b class="caret"></b>
+								</a>
+								<ul class="dropdown-menu">
+									<li><%= link_to "Profile", current_user %></li>
+									<li><%= link_to "Settings", "#" %></li>
+									<li class="divider"></li>
+									<li><%= link_to "Log out", logout_path, method: "delete" %></li>
+								</ul>
+							</li>
+						<% else %>
+							<li><%= link_to "Log in", login_path %></li>
+						<% end %>
           </ul>
           </ul>
         </nav>
         </nav>
       </div>
       </div>
-    </header>
+    </header>
\ No newline at end of file

config/routes.rb

 Rails.application.routes.draw do
 Rails.application.routes.draw do
+  get 'sessions/new'
+
   get 'users/new'
   get 'users/new'
 
 
   root             'static_pages#home'
   root             'static_pages#home'
   get 'help'    => 'static_pages#help'
   get 'help'    => 'static_pages#help'
   get 'about'   => 'static_pages#about'
   get 'about'   => 'static_pages#about'
   get 'contact' => 'static_pages#contact'
   get 'contact' => 'static_pages#contact'
-  get 'signup' => 'users#new'
+  get 'signup'  => 'users#new'
+	get 'login'		=> 'sessions#new'
+	post 'login'	=> 'sessions#create'
+	delete 'logout'	=> 'sessions#destroy'
   resources :users
   resources :users
 end
 end