anchor.diff:  
       <h3>Invite people to join one of your groups:</h3>
   
  +    <% if @model.group %>
  +        <% model_group_id = @model.group.id %>
  +    <% else %>
  +        <% model_group_id = -1 %>
  +    <% end %>
  +
       <% form_tag :controller => "membership", :action => :invite_people do |form| %>
  -     <%= select("group", "id", @person.groups.to_hash, :selected => @model.group.id) %>
  +    <%= 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>
  
positive.code:         <% group.memberships.each do |membership| %>
          <li><%= membership.person.fullname -%>
            <% if membership.status == 'pending' %>
               (<%= link_to "approve", :controller => :membership, :action => :approve_membership, :id => membership.id %>)
            <% end %>
  
            <% if membership.person != @person %>
               (<%= link_to "remove", :controller => :membership, :action => :leave, :id => membership.id %>)
                <% if membership.is_administrator? %>
               (<%= link_to "remove administrator", :controller => :membership, :action => :remove_administrator, :id => membership.id %>)
                <% else %>
               (<%= link_to "make administrator", :controller => :membership, :action => :make_administrator, :id => membership.id %>)
                <% end %>
            <% end %>
          </li>
          <% end %>
  
negative.code:   <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="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>
  