The name(sort) Does not exist in current context

Question

// Here Is My Code  

using DemoGrids.Models;

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.Mvc;

namespace DemoGrids.Controllers

{

public class DemoController : Controller

{

// GET: Demo

public ActionResult Index()

{

return View();

}

public JsonResult GetCustomers(String Word, int Page, int rows, string searchString)

{

using (DatabaseContext db = new DatabaseContext())

{

int PageIndex = Convert.ToInt32(Page) - 1;

int PageSize = rows;

var Results = db.Customers.Select(

a => new

{

a.CustomerId,

a.ContactName,

a.ContactTitle,

a.City,

a.PostalCode,

a.Country,

a.Phone,

});

int totalRecords = Results.Count();

var totalPages = (int)Math.Ceiling((float)totalRecords / (float)rows);

// I a m Getting Error Here  Below  Line 

if (sort.ToUpper() == "DESC")

{

Results = Results.OrderByDescending(s => s.CustomerId);

Results = Results.Skip(PageIndex * PageSize).Take(PageSize);

}

else

{

Results = Results.OrderBy(s => s.CustomerId);

Results = Results.Skip(PageIndex * PageSize).Take(PageSize);

}

if (!string.IsNullOrEmpty(searchString))

{

Results = Results.Where(m => m.Country == searchString);

}

var jsonData = new

{

total = totalPages,

Page,

records = totalRecords,

rows = Results

};

return Json(jsonData, JsonRequestBehavior.AllowGet);

}

}

}

}