I'm getting the above error in my Rails app. I have the following Stripe code in my Booking model -

**booking.rb**

```
    class Booking < ActiveRecord::Base

    belongs_to :event
    belongs_to :user

    validates :quantity, presence: true, numericality: { greater_than: 0 }
    validates :event, presence: true, numericality: {greater_than_or_equal_to: 0 }

    before_save :set_price_to_zero_if_free

    def set_price_to_zero_if_free
       self.event.price >= 1    unless self.event.is_free
    end

    def reserve
        # Don't process this booking if it isn't valid
        #return unless valid?

        # We can always set this, even for free events because their price will be 0.
        #self.total_amount = booking.quantity * event.price

            # Free events don't need to do anything special
            if event.is_free?
            save!

            # Paid events should charge the customer's card
        else

            begin
                charge = Stripe::Charge.create(
                    amount: total_amount,
                    currency: "gbp",
                    source: 'token', 
                    description: "Booking created for amount #{total_amount}")
                    self.stripe_charge_id = charge.id
                    save!
            rescue Stripe::CardError => e
            errors.add(:base, e.message)
            false
            end
        end 
    end
end

```

**bookings\_controller.rb**

```
  class BookingsController < ApplicationController

    before_action :authenticate_user!

    def new
        # booking form
        # I need to find the event that we're making a booking on
        @event = Event.find(params[:event_id])
        # and because the event "has_many :bookings"
        @booking = @event.bookings.new(quantity: params[:quantity])
        # which person is booking the event?
        @booking.user = current_user
        #@booking.quantity = @booking.quantity
        #@total_amount = @booking.quantity.to_f * @event.price.to_f

    end

    def create

        # actually process the booking
        @event = Event.find(params[:event_id])
        @booking = @event.bookings.new(booking_params)
        @booking.user = current_user

            if 
                @booking.reserve
                flash[:success] = "Your place on our event has been booked"
                redirect_to event_path(@event)
            else
                flash[:error] = "Booking unsuccessful"
                render "new"
            end
    end

    private

    def booking_params
        params.require(:booking).permit(:stripe_token, :quantity, :event_id, :stripe_charge_id)
    end

end

```

**booking.new.html.erb**

```
    <div class="col-md-6 col-md-offset-3" id="eventshow">
  <div class="row">
    <div class="panel panel-default">
        <div class="panel-heading">
            <h2>Confirm Your Booking</h2>
        </div>
                  <div class="calculate-total">
                              <p>
                                  Confirm number of spaces you wish to book here:
                                    <input type="number" placeholder="1"  min="1" value="1" class="num-spaces">
                              </p>
                                <p>
                                    Total Amount
                                    £<span class="total" data-unit-cost="<%= @event.price %>">0</span>
                                </p>
                          </div>

                <%= simple_form_for [@event, @booking], id: "new_booking" do |form| %>

                 <span class="payment-errors"></span>

                <div class="form-row">
                    <label>
                      <span>Card Number</span>
                      <input type="text" size="20" data-stripe="number"/>
                    </label>
                </div>

                <div class="form-row">
                  <label>
                  <span>CVC</span>
                  <input type="text" size="4" data-stripe="cvc"/>
                  </label>
                </div>

                <div class="form-row">
                    <label>
                        <span>Expiration (MM/YYYY)</span>
                        <input type="text" size="2" data-stripe="exp-month"/>
                    </label>
                    <span> / </span>
                    <input type="text" size="4" data-stripe="exp-year"/>
                </div>
            </div>
            <div class="panel-footer">    

               <%= form.button :submit %>

            </div> 

<% end %>
<% end %>

      </div>
  </div>
</div>  

<script type="text/javascript">
    $('.calculate-total input').on('keyup change', calculateBookingPrice);

function calculateBookingPrice() {
  var unitCost = parseFloat($('.calculate-total .total').data('unit-cost')),
      numSpaces = parseInt($('.calculate-total .num-spaces').val()),
      total = (numSpaces * unitCost).toFixed(2);

  if (isNaN(total)) {
    total = 0;
  }

  $('.calculate-total span.total').text(total);
}

  $(document).ready(calculateBookingPrice)

</script>

<script type="text/javascript" src="https://js.stripe.com/v2/"></script>

<script type="text/javascript">
  Stripe.setPublishableKey('<%= STRIPE_PUBLIC_KEY %>');
  var stripeResponseHandler = function(status, response) {
    var $form = $('#new_booking');

    if (response.error) {
    // Show the errors on the form
    $form.find('.payment-errors').text(response.error.message);
    $form.find('input[type=submit]').prop('disabled', false);
    } else {
    // token contains id, last4, and card type
    var token = response.id;
    // Insert the token into the form so it gets submitted to the server
    $form.append($('<input type="hidden" name="booking[stripe_token]"     />').val(token));
    // and submit
    $form.get(0).submit();
    }
  };

  // jQuery(function($)  { - changed to the line below
  $(document).on("ready page:load", function () {

    $('#new_booking').submit(function(event) {
      var $form = $(this);

      // Disable the submit button to prevent repeated clicks
      $form.find('input[type=submit]').prop('disabled', true);

      Stripe.card.createToken($form, stripeResponseHandler);

      // Prevent the form from submitting with the default action
      return false;
    });
  });
</script>

```

I don't understand why I'm getting the error when I'm clearly including source within my stripe code. I've expressed it above as self.stripe\_token but I've tried just stripe\_token but still get the same error. My understanding is I need to provide either source or customer, not both, and that it needs to be source rather than customer.

What am I missing?