radiobuttonlist Value is not saved when saving on where the problem is?
<form id="form1" runat="server">
 <div>
 <asp:RadioButtonList ID="rblShippers" runat="server">
 
 </asp:RadioButtonList>
 <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button" />
 </div>
 </form>
////////////////////////////////////////
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;
public partial class _Default : System.Web.UI.Page
{
 protected void Page_Load(object sender, EventArgs e)
 {
string strConnString = "data source=.;initial catalog=saeed;integrated security=true";
 using (SqlConnection con = new SqlConnection(strConnString))
 {
SqlCommand cmd = new SqlCommand("Select * from Categories", con);
 SqlDataAdapter adp = new SqlDataAdapter(cmd);
 DataTable dt = new DataTable();
 adp.Fill(dt);
 rblShippers.DataSource = dt;
 rblShippers.DataTextField = "CategoryName";
 rblShippers.DataValueField = "CategoryID";
 rblShippers.DataBind();
 }
 }
 protected void Button1_Click(object sender, EventArgs e)
 {
 string strConnString = "data source=.;initial catalog=saeed;integrated security=true";
 using (SqlConnection con = new SqlConnection(strConnString))
 {
 string query = "insert into tbl_ss(name) VALUES(@name)";
 using (SqlCommand cmd = new SqlCommand(query))
 {
 cmd.Connection = con;
cmd.Parameters.AddWithValue("@name",rblShippers.SelectedIndex);
 con.Open();
 cmd.ExecuteNonQuery();
 con.Close();
 
 }
 }
 }
}