reading child tags from xml file

protected void Page_Load(object sender, EventArgs e)
    {
        DataSet ds = new DataSet();

        ds.ReadXml(MapPath("~/app_data/countries.xml"));

        BindCountries(ds.Tables["country"]);
        BindStates(ds.Tables["state"]);
        BindCities(ds.Tables["city"]);
    }

    void BindCountries(DataTable dtblC)
    {
        ddlCountry.Items.Clear();
        ddlCountry.DataSource = dtblC;
        ddlCountry.DataTextField = "name";
        ddlCountry.DataValueField = "id";
        ddlCountry.DataBind();
    }

    void BindStates(DataTable dtblC)
    {
        ddlStates.Items.Clear();
        ddlStates.DataSource = dtblC;
        ddlStates.DataTextField = "name";
        ddlStates.DataValueField = "id";
        ddlStates.DataBind();
    }

    void BindCities(DataTable dtblC)
    {
        ddlCities.Items.Clear();
        ddlCities.DataSource = dtblC;
        ddlCities.DataTextField = "name";
        ddlCities.DataValueField = "id";
        ddlCities.DataBind();
    }