Ruby on Rails "Form" Inserting to associated tables

Hello my fellow programmers!

Noob here with a noob question. I just began ruby on rails 3 weeks ago. So its save to say that i am fierily new with it. I am building a order management system that contains 2 tables. :customer and :order. I can destroy, show, and possibly edit. But i can only create for customer and not for order that comes with it. This is the code that i have so far

---

class Order < ActiveRecord::Base

belongs_to :customer

end

---

class Customer < ActiveRecord::Base

has_many :orders

end

---

def new
    @orders = Order.new
    @customer = Customer.new ({:voornaam => "ABC"})
 end

 def create
    @customer = Customer.new(customer_params)
    if @customer.save
    orders = Order.where(params(order_params))
    @customer.orders << orders
    flash[:notice] = "Subject created successfully"
    redirect_to(:action => 'index')
    else
    render('new') 
  end
end


def customer_params
    #same as using "params[:subject]", expect that it:
    # - raises an error if :subject is not present
    # - allows listed attributes to be mass-assigned
   params.require(:customer).permit(:voornaam, :achternaam)
  end

  private

  def order_params
    #same as using "params[:subject]", expect that it:
    # - raises an error if :subject is not present
    # - allows listed attributes to be mass-assigned
   params.require(:customer).permit(:pakket, :datum_bestelt, :verstuurt, :datum_verstuurt, :tweede_exemplaar, :packettracer_ID)
  end
end

Create Order

<%= form_for(:customer, :url=> {:action => 'create'}) do |f| %>

<table summary="subject form fields">
    <tr>
        <th>Voornaam</th>
        <td><%= f.text_field(:voornaam) %></td>
    </tr>
    <tr>
        <th>Achternaam</th>
        <td><%= f.text_field(:achternaam) %></td>
    </tr>
    <%= f.fields_for :order do |s| %>
    <tr>
        <th>pakket</th>
        <td><%= s.text_field(:pakket) %></td>
    </tr>
    <tr>
        <th>datum_bestelt</th>
        <td><%= s.text_field(:datum_bestelt) %></td>
    </tr>
    <tr>
        <th>verstuurt</th>
        <td><%= s.text_field(:verstuurt) %></td>
    </tr>
    <tr>
        <th>datum_verstuurt</th>
        <td><%= s.text_field(:datum_verstuurt) %></td>
    </tr>
    <tr>
        <th>tweede_exemplaar</th>
        <td><%= s.text_field(:tweede_exemplaar) %></td>
    </tr>
    <tr>
        <th>packettracer_ID</th>
        <td><%= s.text_field(:packettracer_ID) %></td>
    </tr>
    <% end %>

</table>