<%= labelled_fields_for :pref, @user.pref do |pref_fields| %> <%= pref_fields.collection_check_boxes :auto_watch_on, auto_watch_on_options, :last, :first, :checked => @user.pref.auto_watch_on do |b| %>

<%= b.check_box %> <%= b.label %>

<% end %> <% end %>