Railsgirls javascript submit

application.js

jQuery(document).ready(function() {
  $('.update-done :checkbox').on('change', function () {
    var checkbox = $(this);
    var form = checkbox.parent('form');
    $.ajax(form.attr('action'), {type: 'PUT', data: form.serialize()});
  });
});

index.html.erb

    <td class="update-done">
      <%= form_for idea , :url => update_done_idea_path(idea), :method=>"put" do |f| %>
        <%= f.check_box :done %>
      <% end %>
    </td>

routes.rb

  resources :ideas do
    put :update_done, :on => :member
  end