Nested Model and It's step to make it happen in rails 3

gistfile1.rb

How to setup netsed model in Rails 3
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CREATE TABLE `books` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `title` varchar(255) DEFAULT NULL,
  `description` text,
  `imported_from` varchar(255) DEFAULT NULL,
  `created_at` datetime DEFAULT NULL,
  `updated_at` datetime DEFAULT NULL
  PRIMARY KEY (`id`)
)


CREATE TABLE `books_isbns` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `isbn` varchar(255) DEFAULT NULL,
  `book_id` int(11) DEFAULT NULL,
  `created_at` datetime DEFAULT NULL,
  `updated_at` datetime DEFAULT NULL,
  PRIMARY KEY (`id`)
)


- Create models 
class Book < ActiveRecord::Base
  # Book ISBN
  has_many :books_isbn, :dependent => :destroy
  accepts_nested_attributes_for :books_isbn, :allow_destroy => true
  attr_accessible :books_isbn_attributes
end

class BooksIsbn < ActiveRecord::Base
  belongs_to :book
end


- Controller
 > Input Page or Get Action
  def add
    @book = Book.new()
    @book.books_isbn.build
  end

  def save
    begin
      Book.transaction do
        @book = Book.new(params[:book])
        @book.save ? redirect_to(book_path(@book)) : render(:action => :new)
      end # transaction end
    rescue Exception => e
      Rails.logger.info "Problem in creating book : #{ e.message }"        
    end

    # render...
  end


- In view
  <%= form_for(@book, :url => book_save_details_path(:id => @book), :html =>{:multipart => true, :method => :post}) do |f| %>
    <%= f.fields_for :books_isbn do | isbn | %>
      <%= isbn.label :isbn %>
      <%= isbn.text_field :isbn %>
    <% end %>
  <% end %>

- Generated field name 
  book[books_isbn_attributes][0][isbn]