anchor.diff:        :wrap_object => Proc.new {|participant| participant.build_event; participant }
       %> 
     </fieldset>
  +  </div>
   
  +  <div class="col-md-5">
     <h2>Constraints</h2>
   
     <fieldset id="event-constraints">
       Edit constraints here.
     </fieldset>
  +  </div>
   
  -  <%= f.submit %> 
  +</div>
  +<%= f.submit %>
   <% end %>
  
positive.code:     </ul>
    </fieldset>
  
    <h2>Participants</h2>
  
    <fieldset id="event-participants">
  
negative.code: <h1>Edit: <%= @event.title %></h1>
  
  <%= form_for @event do |f| %>
  <div class="container">
    <%= render 'form_errors' %>
    <fieldset>
      <ul>
  