Json Data Not showing in the grid (in Master pages)

See more:

ASP.NET

jQuery

<script type="text/javascript">
        $(document).ready(function () {
            $.ajax({
                type: "POST",
                contentType: "application/json; charset=utf-8",
                url: "WebForm3.aspx/BindDatatable",
                data: "{}",
                dataType: "json",
                success: function (data) {
                    for (var i = 0; i < data.d.length; i++) {
                       $("#gvDetails").append("<table><tbody><tr><td>" + (data.d[i].Consumption) + "</td><td>" + (data.d[i].MeterTimestamp) + "</td></tr></tbody></table>");
                    }
                },
                error: function (result) {
                    alert("Error");
                }
            });
        });
    </script>

  <asp:GridView ID="gvDetails" runat="server" AutoGenerateColumns="false">
        <HeaderStyle BackColor="#DC5807" Font-Bold="true" ForeColor="White" />

.cs code like

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Script.Services;
using System.Data;


namespace WaterMeter_Solution
{
    public partial class WebForm3 : System.Web.UI.Page
    {

        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                BindColumnToGridview();
            }
        }
        /// <summary>
        /// This method is used to bind dummy row to gridview to bind data using JQuery
        /// </summary>
        private void BindColumnToGridview()
        {
            DataTable dt = new DataTable();
            dt.Columns.AddRange(new DataColumn[] { new DataColumn("Consumption"), new DataColumn("MeterTimestamp", typeof(DateTime)) });
            dt.Rows.Add();
            gvDetails.DataSource = dt;
            gvDetails.DataBind();
            gvDetails.Rows[0].Visible = false;
        }

        [WebMethod]
        public static UserDetails[] BindDatatable()
        {
            DateTime FromDate = DateTime.Today;
            DataTable dt = new DataTable();
            List<userdetails> details = new List<userdetails>();
            {
                using (OracleDataBase objdb = new OracleDataBase())
                {
                    dt = objdb.GetServiceWiseConsumption("PR_GET_RECORDS_PER_SERVICE", 6, FromDate);
                    foreach (DataRow dtrow in dt.Rows)
                    {
                        UserDetails user = new UserDetails();
                     //   user.UserId = dtrow["UserId"].ToString();
                        user.Consumption = dtrow["Consumption"].ToString();
                        user.MeterTimestamp = dtrow["MeterTimestamp"].ToString();
                        details.Add(user);
                    }
                }
            }
            return details.ToArray();
        }
        public class UserDetails
        {
            //public string UserId { get; set; }
            public string Consumption { get; set; }
            public string MeterTimestamp { get; set; }
        }

    }
}

like this am using in master page concept but it is not showing grid data in normal pages it is working fine y???
it is not showing can any one help me for this it s very urgent.