app/views/admin/taxon_instruments/_form.html.erb
<%= form_for [:admin, @taxon_concept, @taxon_instrument] do |f| %>
<%= error_messages_for(@taxon_instrument) %>
<%= f.hidden_field :taxon_concept_id %>
<div class="control-group">
<%= f.label :instrument_id %>
<%= f.select :instrument_id,
options_from_collection_for_select(@instruments, :id, :name, @taxon_instrument.instrument_id )
%>
</div>
<div class="control-group">
<%= f.label :effective_from %>
<%= f.text_field :effective_from, :class => "datepicker", :value => @taxon_instrument.effective_from_formatted %>
</div>
<%= f.submit %>
<% end %>