app/views/retention_periods/edit.html.erb
<div id="content_detail" class="ui-corner-all">
<h1 class="title"><%= t('page.editing', :model => t('activerecord.models.retention_period')) %></h1>
<div id="content_list">
<%= render 'form' %>
</div>
</div>
<div id="submenu" class="ui-corner-all">
<ul>
<li><%= link_to t('page.show'), @retention_period %></li>
<li><%= link_to t('page.back'), retention_periods_path %></li>
</ul>
</div>