Am Getting An Error "Undefined " While Executing Update Web Method Which I Called In Jquery Ajax Can U Tell Me Where Is The Error

update: function (options) {


                           $.ajax({
                               type: "POST",
                               url: url1,
                               cache: false,
                               contentType: "application/json; charset=utf-8",
                               // data: JSON.stringify($("#cid").data("grid").dataSource.select()),
                               data: "{'id':'" + $("#id").val() + "','name':'" + $("#name").val() + "','age':'" + $("#age").val() + "'}",
                               dataType: "json",
                               success: function (result) {
                                   if (result.d !== "success") {
                                       alert(result.d);
                                   }
                                   dataSource.read();

                               },
                               error: function (result) {
                                   alert(result.Id);

                               }
                           });
                           

                       },

[System.Web.Services.WebMethod]
        public static string UpdateData(string id, string name,string age)
        {
            //DataSet ds = null;
            //return ds;
            string strResult = "";

            DataTable dt = new DataTable();

            SqlConnection con1 = new SqlConnection("Database=project;Data Source=.;Trusted_Connection=true");
            SqlCommand updateData = new SqlCommand();

            updateData.Connection = con1;
            updateData.CommandType = CommandType.StoredProcedure;
            updateData.CommandText = "updating";
            updateData.Parameters.Add("@id", SqlDbType.NVarChar).Value = id;
            updateData.Parameters.Add("@name", SqlDbType.NVarChar).Value = name;

            updateData.CommandType = CommandType.StoredProcedure;
            SqlDataAdapter dataAdapter = new SqlDataAdapter();
            DataSet dataSet = new DataSet();
            dataAdapter.SelectCommand = updateData;
            dataAdapter.Fill(dataSet);
            dt = dataSet.Tables[0];
            if (dt.Rows.Count > 0)
            {

                strResult = Convert.ToString(dt.Rows[0][0]);
                //strResult = strResult.Replace("<error>", "");
                //strResult = strResult.Replace("</error>", "");
                // RenderXML(dt, strResult);
            }
            return strResult;
        }