Rails 3 Nested Model Form with Javascript

I have created a nested model form for Lessons to Questions and Answers. It was not picking up the coffee script so I have add it the coffee code as Javascript but i am get an error and Add Question is not working. Anyone and assist please.

Lesson.rb

has_many :questions
accepts_nested_attributes_for :questions, :allow_destroy => true

Question.rb

belongs_to :lesson
has_many :answers
accepts_nested_attributes_for :answers, :allow_destroy => true

Answer.rb

belongs_to :question

application_helper.rb

def link_to_add_fields(name, f, association) new_object = f.object.send(association).klass.new
    id = new_object.object_id
   fields = f.fields_for(association, new_object, :child_index => id) do   |builder|
  render(association.to_s.singularize + "_fields", :f => builder)
end
link_to(name, '#', :class => "add_fields", :data => {:id => id, :fields =>   fields.gsub("\n", "")}) end

admin/lessons/_form.html.erb

 <%= form_for([:admin,@lesson]) do |f| %>
          <% if @lesson.errors.any? %>
            <div class="notification error png_bg">
                <a href="#" class="close"><img src="/assets/admin/icons/cross_grey_small.png" title="Close this notification" alt="close" /></a>
                <div>
                <h2><%= pluralize(@lesson.errors.count, "error") %></h2>

                  <ul>
                  <% @lesson.errors.full_messages.each do |msg| %>
                    <li><%= msg %></li>
                  <% end %>
                  </ul>
                </div>                          
            </div>
          <% end %>

  <label class="formlabel">Lesson Title</label>
  <%= f.text_field :title  %>

 <%= f.fields_for :questions do |builder| %>
 <%= render 'question_fields', :f => builder %>
 <% end %>
 <%= link_to_add_fields "Add Question", f, :questions %>

 <%= f.submit 'Save', :class => 'button' %>

_question_fields.html.erb

 <fieldset>
    <%= f.label :content, "Question" %><br />
    <%= f.text_area :content %><br />
    <%= f.check_box :_destroy %>
    <%= f.label :_destroy, "Remove Question" %>
    <%= f.fields_for :answers do |builder| %>
       <%= render 'answer_fields', :f => builder %>
    <% end %>
    <%= link_to_add_fields "Add Answer", f, :answers %>
 </fieldset>

_answer_fields.html.erb

 <fieldset>
    <%= f.label :content, "Answer" %>
    <%= f.text_field :content %>
    <%= f.check_box :_destroy %>
    <%= f.label :_destroy, "Remove Answer" %>
 </fieldset>

Here is the javascript I have added just before the end of the the head tag. I am getting an error of "$('form').on is not a function. (In '$('form').on', '$('form'....

<script>
            jQuery(function() {
              $('form').on('click', '.remove_fields', function(event) {
                $(this).prev('input[type=hidden]').val('1');
                $(this).closest('fieldset').hide();
                return event.preventDefault();
              });
              return $('form').on('click', '.add_fields', function(event) {
                var regexp, time;
                time = new Date().getTime();
                regexp = new RegExp($(this).data('id'), 'g');
                $(this).before($(this).data('fields').replace(regexp, time));
                return event.preventDefault();
              });
            });
        </script>