How to use Coookies

When i used authenticate by session in view i used this code <code> <% if @user.id != session[:id]%> <%= link_to 'Отправить Сообщение',           :controller => 'users',           :action => 'messages',           :id => @user,           :anchor => 'send_message'           %> <% end %> </code>

Now i authenticated user by cookies, how can i change above code for it'll work