asp.net web forms [WebMethod]

I have a problem with my [WebMethod] when I return Json data List<Contract> from DB using Entity Framework

function populateData(pageIndex) {
                // populate data from database
                $.ajax({
                    url: "/Pages/App/http://ift.tt/2dKG4RV",
                    data: "{pageNo: " + pageIndex + ", noOfRecord: 7}",
                    type: "POST",
                    dataType: "json",
                    contentType: "application/json; charset=utf-8",
                    success: OnSuccess,
                    error: onError
                });
            }
            function OnSuccess(data) {

                alert('good');
            }
            function onError() {
                alert('Failed!');
                $('#LoadingPanel').css('display', 'none');
            }

This my WeMethod.

[WebMethod]
    [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
    public static List<Contract> PopulateDataByJquery(int pageNo, int noOfRecord)
    {
        System.Threading.Thread.Sleep(2000);
        Entities4 db = new Entities4();
        List<Contract> data = new List<Contract>();
        int skip = (pageNo - 1) * noOfRecord;
        data = db.Contracts.Include("PhysicalPerson").Include("Product").OrderBy(a => a.Id).Skip(skip).Take(noOfRecord).ToList(); 
        return data;
    }

I every time getting ajax error, help me please! I don't know how it fix.