User control dataset object not set to an instance

Hi Experts,

I'm trying to load a dropdownlistbox in a user control.    I receive the following error when I try to view the control in web browser: Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.  Please find below my user control.  The code that cause the exception is DDLCountry.DataSource = dataTable.DefaultView; Your help is appreciated.

namespace CWebSite1
{
using System;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Web;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

public abstract class CountryDropDown : System.Web.UI.UserControl
{
protected System.Web.UI.WebControls.DropDownList DropDownList1;
protected System.Web.UI.WebControls.DropDownList DDLCountry;

public delegate void ListChangedHandler(object sender, CountryListArgs e);
public event ListChangedHandler ListChanged;

protected virtual void OnListChanged(CountryListArgs e)
{
if (ListChanged != null)
      ListChanged(this, e);
}
   
public CountryDropDown()
{
     this.Init += new System.EventHandler(Page_Init);
}

private void Page_Load(object sender, System.EventArgs e)
{
if (!IsPostBack)
{
      DataSet DS1 = new DataSet();
      DS1 = DCPIntranet_ClassLibrary.
                DCPIntranet_Admin_code_to_execute_stored_procedures.
                Get_all_countries();

      if (DS1.Tables[0].Rows.Count != 0)
      {
      DataTable dataTable = DS1.Tables[0];
      DDLCountry.DataSource = dataTable.DefaultView; /*this is were I get the exception*/
      DDLCountry.DataTextField = "Country_name";
      DDLCountry.DataBind(  );
       }
}
}

private void Page_Init(object sender, EventArgs e)
{
InitializeComponent(  );
}
#region Web Form Designer generated code
///        Required method for Designer support - do not modify
///        the contents of this method with the code editor.
/// </summary>
private void InitializeComponent(  )
{
     this.Load += new System.EventHandler(this.Page_Load);
}
#endregion

public class CountryListArgs : EventArgs
{
public string countrySelected;
}

private void OnSelectedIndexChanged(object sender, System.EventArgs e)
{
CountryListArgs countrylistargs = new CountryListArgs();
countrylistargs.countrySelected= DDLCountry.SelectedItem.ToString();
OnListChanged(countrylistargs);
}
}
}