/**
  * checkout and process payment when post back 
  * @param $order object ET_Order
  * @since 1.0
  * @author Dakachi
  */
 function do_checkout(ET_Order $order)
 {
     $order_datas = $order->get_order_data();
     switch (strtoupper($order_datas['status'])) {
         case 'COMPLETED':
         case 'PUBLISH':
             $paymentStatus = 'Completed';
             break;
         case 'PROCESSING':
         case 'PENDING':
             $paymentStatus = 'Pending';
             break;
         case 'DRAFT':
             $paymentStatus = 'fraud';
             break;
         default:
             $paymentStatus = 'fraud';
             break;
     }
     /**
      * should add a return here, check fraud and get the post back info
      * @since 1.2
      * @author Dakachi
      */
     if ('fraud' === $paymentStatus) {
         return $this->do_checkout_get_back($order);
     }
     // return
     return array('ACK' => in_array(strtoupper($order_datas['status']), array('COMPLETED', 'PUBLISH', 'PROCESSING', 'PENDING')), 'payment' => 'simplePaypal', 'payment_status' => $paymentStatus);
 }