Bind Grid View Using Jquery And Give Header Text From Code Behind

JQUERY :-

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <script type="text/jscript">
        $(document).ready(function () {
            $.ajax({
                type: "POST",
                contentType: "application/json; charset=utf-8",
                url: "BindgridusingWebMethod.aspx/BindDatatable",
                data: "{}",
                dataType: "json",
                success: function (data) {
                    for (var i = 0; i < data.d.length; i++) {
                        $("#gvDetails").append("<tr><td>" + data.d[i].UserId + "</td><td>" + data.d[i].UserName + "</td><td>" + data.d[i].Location + "</td></tr>");
                    }
                },
                error: function (result) {
                    alert("Error");
                }
            });
        });
    </script>

ASPX CODE :-
<asp:Button ID="btnshowgrid" runat="server" Text="Show Gridview" OnClick="btnshowgrid_Click" />&nbsp;<asp:Button
        ID="clear" runat="server" Text="Clear" onclick="clear_Click" />
<asp:GridView ID="gvDetails" runat="server" >
            <HeaderStyle BackColor="#474747" Font-Bold="true" ForeColor="White" />
        </asp:GridView>

NAMESPACE :-

using System;
using System.Data;
using System.Data.SqlClient;
using System.Web.Services;
using System.Collections.Generic;

CODE BEHIND :-

private void BindColumnToGridview()
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("fullname");
            dt.Columns.Add("DOB");
            dt.Columns.Add("Gender");
            dt.Rows.Add();
            gvDetails.DataSource = dt;
            gvDetails.DataBind();
            gvDetails.Rows[0].Visible = false;
        }

[WebMethod]
        public static entity[] BindDatatable()
        {
            DataTable dt = new DataTable();
            List<entity> details = new List<entity>();

            using (SqlConnection con = new SqlConnection("Data Source=10.1.1.1;Initial Catalog=DailyTaskoskar;Persist Security Info=True;User ID=Username;Password=Password"))
            {
                using (SqlCommand cmd = new SqlCommand("SELECT FullName,CONVERT(varchar(30),DOB,101) AS DOB,Gender    FROM form ", con))
                {
                    con.Open();
                    SqlDataAdapter da = new SqlDataAdapter(cmd);
                    da.Fill(dt);
                    foreach (DataRow dtrow in dt.Rows)
                    {
                        entity user = new entity();
                        user.UserId = dtrow["fullname"].ToString();
                        user.UserName = dtrow["DOB"].ToString();
                        user.Location = dtrow["Gender"].ToString();
                        details.Add(user);
                    }
                }
            }
            return details.ToArray();
        }

protected void btnshowgrid_Click(object sender, EventArgs e)
        {
            BindColumnToGridview();
         }

protected void clear_Click(object sender, EventArgs e)
        {
            gvDetails.DataSource = null;
            gvDetails.DataBind();
        }

Click on Button :-