anchor.diff:    <div id="group_tabs">
       <ul class="subsection_tabs">
         <li class="tab"><a id="your-groups-tab" href="#your-groups-div">Your groups</a></li>
  -<!--      <li class="tab"><a id="join-group-tab" href="#join-group-div">Join a group</a></li> ->
  +      <!-- <li class="tab"><a id="join-group-tab" href="#join-group-div">Join a group</a></li> -->
         <li class="tab"><a id="create-group-tab" href="#create-group-div">Create</a></li>
         <li class="tab"><a id="manage-groups-tab" href="#manage-groups-div">Manage</a></li>
       </ul>
  
positive.code: 
      <h3>Invite people to join one of your groups:</h3>
  
      <% form_tag :controller => "membership", :action => :invite_people do |form| %>
       <%= select("group", "id", @person.groups.to_hash, :selected => @model.group.id) %>
      <p>E-mail addresses, separated by commas:</p>
      <p><%= text_area_tag "invitees" %></p>
      <p><%= submit_tag "Invite users" %></p>
  
negative.code:     <ul>
        <% @person.memberships.each do |membership| %>
        <li><%= membership.group.name %>
          (<%= link_to "leave", :controller => :membership, :action => :leave, :id => membership.id %>)
        </li>
        <% end %>
      </ul>
    </div>
  