app/views/role_replacements/_form.html.erb
<%= labelled_form_for role_replacement, url: url, html: { id: 'role-replacement-form' } do |f| %>
<%= error_messages_for role_replacement %>
<div class="box tabular">
<p><%= f.collection_select :role_before_id, role_before_list, :id, :name %></p>
<p><%= f.collection_select :role_after_id, Role.sorted, :id, :name %></p>
</div>
<%= submit_tag message %>
<% end %>