# File lib/active_merchant/billing/integrations/action_view_helper.rb, line 42
        def payment_service_for(order, account, options = {}, &proc)          
          raise ArgumentError, "Missing block" unless block_given?

          integration_module = ActiveMerchant::Billing::Integrations.const_get(options.delete(:service).to_s.camelize)

          result = []
          result << form_tag(integration_module.service_url, options.delete(:html) || {})
          
          service_class = integration_module.const_get('Helper')
          service = service_class.new(order, account, options)

          result << capture(service, &proc)

          service.form_fields.each do |field, value|
            result << hidden_field_tag(field, value)
          end
         
          result << '</form>'
          result= result.join("\n")
          
          concat(result.respond_to?(:html_safe) ? result.html_safe : result)
          nil
        end