Populating a Gridview with Ajax data

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C#

ASP.NET

Gridview

I am getting no error codes just clicking Button1 and nothing happens.

I was an having error with the "length" in data.d so I added "var data1 = data.d" that did not corrected that.

Any suggestions?

Default.aspx

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script type="text/javascript">
    $(function () {
        $("#<%= Button1.ClientID %>").click(function () {
            $.ajax({
                type: "POST",
                url: "Default.aspx/gvAjax",
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                data: "{}",
                async: true,
                cache: false,
                success: function (data) {
                    $("#<%= GridView1.ClientID %>").empty();
                    var data1 = data.d;
                    for (var i = 0; i < data1.length; i++) {

                        $("#<%= GridView1.ClientID %>").append("<tr><td>" + data1[i].Id + "</td><td>" + data1[i].col1 + "</td><td>" + data1[i].col2 + "</td><td>" + data1[i].col3 + "</td></tr>");
                    }
                },
                error: function (x, e) {
                    alert("Error: " + x.responseText);
                }
            });
        });
    });

Default.aspx.cs

[System.Web.Services.WebMethod]
public static string gvAjax(int id)
{
    List<Table1> gvlist = new List<Table1>();
    var json1 = "";
    DataSet ds = new DataSet();
    DataTable dt = new DataTable();
    string connStr = ConfigurationManager.ConnectionStrings["connContext"].ConnectionString;
    string cmdStr = "SELECT * FROM [Table1];";
    using (SqlConnection conn = new SqlConnection(connStr))
    {
        using (SqlCommand cmd = new SqlCommand(cmdStr, conn))
        {
            conn.Open();
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))
            {
                da.Fill(ds);
                dt = ds.Tables[0];
                foreach (DataRow dr in dt.Rows)
                {

                    Table1 tb1 = new Table1();
                    tb1.Id = Convert.ToInt32(dr["Id"]);
                    tb1.col1 = dr["col1"].ToString();
                    tb1.col2 = dr["col2"].ToString();
                    tb1.col3 = dr["col3"].ToString();
                    gvlist.Add(tb1);
                }
            }
        }
        var serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
        json1 = serializer.Serialize(gvlist);
        return json1;
    }
}