using System;

using System.Web.Mvc;

using System.Collections.Generic;

​

namespace HelloWorldMvcApp

{

    public class HomeController : Controller

    {

        public ActionResult Complete(int id)

        {

            bool isValid = blablabla

​

            var model = new CheckoutViewModel

            {

                OrderId = id

            };

​

            if(isValid)

                return View(model);

​

            else

                return View("Error");

​

        }

    }

}