Rails 3 + Ajax: how to access my local form builder instance

Can you use fields_for in your partial, and pass the @object to it? That way you don't need to pass a form builder?

partial:

<%= fields_for object do |f| %>
  f.text_field :field_name
<% end %>

$('#info').html("<%= escape_javascript(render 'my_second_fields_partial', object: @object) %>