populate dropdown on client side

Use the following function

public static List<Country> GetCountries()
    {
         SqlConnection conn;
        string constr = "Initial Catalog="                ";
        conn = new SqlConnection();
        conn.ConnectionString = constr; Session["Constr"].ToString();
        conn.Open();
        string sql = "Select distinct city from LOCATION";
        SqlDataAdapter da = new SqlDataAdapter(sql, conn);
        DataTable dt = new DataTable();
        da.Fill(dt);
        List<Country> items = new List<Country>(); 
{
                (dt.Rows.Count - 1)};
        foreach (DataRow dr in dt.Rows)
        {
            Country country = new Country();
            country.Id = dr["city"].ToString();
            country.Name = dr["city"].ToString();
        }
        return items;
    }