# File lib/active_merchant/billing/gateways/eway_managed.rb, line 53
      def update(billing_id, creditcard, options={})
        post = {}
        
        # Handle our required fields
        requires!(options, :billing_address)

        # Handle eWay specific required fields.
        billing_address = options[:billing_address]
        eway_requires!(billing_address)
        
        post[:managedCustomerID]=billing_id
        add_creditcard(post, creditcard)
        add_address(post, billing_address)
        add_misc_fields(post, options)
             
        commit("UpdateCustomer", post)
      end