public ActionResult GetCities(string id) { citydata = new CityData(); citydata.AddCity(new City { CityID = 1, Name = "1111111", StateID = 1 }); citydata.AddCity(new City { CityID = 2, Name = "2222222", StateID = 1 }); citydata.AddCity(new City { CityID = 3, Name = "33333333", StateID = 2 }); citydata.AddCity(new City { CityID = 4, Name = "44444444", StateID = 2 }); IList <City> citylist = new List <City>(); foreach (var item in citydata.GetList()) { if (item.StateID.ToString().Equals(id)) { citylist.Add(item); } } var json = new JavaScriptSerializer().Serialize(citylist); return(Json(json, JsonRequestBehavior.AllowGet)); }