environment.rb

# config/environment.rb

config.gem "bitfluent-activemerchant", :lib => "activemerchant"

ipay88.rb

# config/initializers/ipay88.rb

ActiveMerchant::Billing::Integrations::Ipay88.merchant_key = "t6mqZRi6UB"

require 'active_merchant/billing/integrations/action_view_helper'
ActionView::Base.send(:include, ActiveMerchant::Billing::Integrations::ActionViewHelper)

orders_controller.rb

# app/controllers/orders_controller.rb

class OrdersController < ApplicationController
  def pay
    @order = Order.find(params[:id])
  end

  def return
    ret = ActiveMerchant::Billing::Integrations::Ipay88.return(request.raw_post)
    if ret.success?
      @order = Order.find(ret.order)
      @order.capture!(:amount => ret.amount)
      flash[:notice] = "Thanks for the payment!"
    else
      flash[:error] = "Payment was unsuccessful: #{ret.error}"
    end
  end
end

pay.html

<form action="https://www.mobile88.com/epayment/entry.asp" method="post">
  <input id="RefNo" name="RefNo" type="hidden" value="1" /> 
  <input id="UserContact" name="UserContact" type="hidden" value="0128888888" /> 
  <input id="UserName" name="UserName" type="hidden" value="Kamal" /> 
  <input id="Signature" name="Signature" type="hidden" value="dpBSyeFdjmlLug36ao1HsIwNoW0=" /> 
  <input id="UserEmail" name="UserEmail" type="hidden" value="[email protected]" /> 
  <input id="Amount" name="Amount" type="hidden" value="10.00" /> 
  <input id="ProdDesc" name="ProdDesc" type="hidden" value="Bioshock 2 and Portal" /> 
  <input id="Currency" name="Currency" type="hidden" value="MYR" /> 
  <input id="MerchantCode" name="MerchantCode" type="hidden" value="YOUR-IPAY88-MERCHANT-CODE" /> 
</form>

pay.html.erb

<% payment_service_for @order.id, 'YOUR-IPAY88-MERCHANT-CODE',
        :amount => @order.total, 
        :currency => 'MYR', 
        :service => :ipay88 do |service| %>

  <% service.customer :name => @order.customer_name,
                     :email => @order.customer_email,
                     :phone => @order.customer_phone %>

  <% service.description @order.items.to_sentence %>

<% end %>

routes.rb

# config/routes.rb

ActionController::Routing::Routes.draw do |map|
  map.resources :orders, :member => { :pay => :get }, :collection => { :return => :post }
end