How to get a state from database in combobox

string strCon = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

    string str;

    SqlCommand com;

    SqlDataAdapter sqlda;

    DataSet ds;



    void bindCountry()

    {

        SqlConnection con = new SqlConnection(strCon);

        str = "select CountryId,CountryName from Country order by CountryName asc";

        com = new SqlCommand(str, con);

        sqlda = new SqlDataAdapter(com);

        ds = new DataSet();

        sqlda.Fill(ds,"Country");

        comCountry.DataSource = ds.Tables["Country"].DefaultView;

        comCountry.ValueMember = "CountryId";

        comCountry.DisplayMember = "CountryName";

    }



// Combobox Selected Country Changed  'Start'



    bindState();



// End

 void bindState()

   {



        SqlConnection con = new SqlConnection(strCon);

        str = "select StateId,StateName from State where Country_Id ='" + comCountry.SelectedValue + "'";

        com = new SqlCommand(str, con);

        sqlda = new SqlDataAdapter(com);

        ds = new DataSet();

        sqlda.Fill(ds,"State");

        comState.DataSource = ds.Tables["State"].DefaultView;

        comState.ValueMember = "StateId";

        comState.DisplayMember = "StateName";

    }