# File lib/active_merchant/billing/gateways/authorize_net.rb, line 156
      def refund(money, identification, options = {})
        requires!(options, :card_number)

        post = { :trans_id => identification,
                 :card_num => options[:card_number]
               }

        post[:first_name] = options[:first_name] if options[:first_name]
        post[:last_name] = options[:last_name] if options[:last_name]
        post[:zip] = options[:zip] if options[:zip]

        add_invoice(post, options)
        add_duplicate_window(post)

        commit('CREDIT', money, post)
      end