module ApplicationHelper 

  # Return a link for use in layout navigation. 
  def nav_link(text, controller, action="index") 
    link_to_unless_current text, :controller => controller, 
                                        :action => action 
  end 
  
  # Return true if some user is logged in, false otherwise.
  def logged_in?
    not session[:user_id].nil?
  end
end