Ruby on Rails

I'm following the tutorial of railscast #88 Dynamic select menus. I got an error in jquery part of it. I'm not a familiar in jquery I just follow his tutorial, I already searched the error.

Error on console

Uncaught Error: Syntax error, unrecognized expression: $serviceprovider_service_id :

_form.html.erb
<%= form_for(@serviceprovider, html: { :multipart => true }, class: 'form-horizontal') do |f| %>          <div class="form-group">              <label class="client-login-label">Service</label>              <%= collection_select(:serviceprovider, :service_id, Service.all, :id, :service, prompt: 'Choose Service') %>              <%#= f.text_field :barangay, class: 'form-control client-login-field', placeholder: 'Barangay' %>        </div>          <div class="form-group">              <label class="client-login-label">Category</label>              <%= grouped_collection_select(:serviceprovider, :category_id, Service.order(:service), :categories, :service, :id, :name, prompt: 'Choose Category') %>              <%#= f.text_field :barangay, class: 'form-control client-login-field', placeholder: 'Barangay' %>        </div>          <div class="form-group">          <%= f.submit("Register", class: 'btn btn-lg btn-success client-signin-btn') %>        </div>      <% end %>
serviceprovider.js.coffee
jQuery ->      categories = $('#serviceprovider_category_id').html()      $('#serviceprovider_service_id').change ->          service = $('#serviceprovider_service_id :selected').text()          options = $(categories).filter("optgroup[label='#{service}']").html()          if options              $('#serviceprovider_category_id').html(options)          else              $('#serviceprovider_category_id').empty()