MySql.Data.MySqlClient.MySqlDataReader.GetOrdinal C# (CSharp) Method

    public override int GetOrdinal(string name)
    {
      if (!isOpen || resultSet == null)
        Throw(new Exception("No current query in data reader"));

      return resultSet.GetOrdinal(name);
    }

        protected void LoginUser(object sender, EventArgs e)
        {
            string connectionString = @"Data Source=db4free.net; Database=centresportif420; user=centresportif420; password=stephane420;";

            using (MySqlConnection cn = new MySqlConnection(connectionString))
            {
                cn.Open();
                queryStr = "SELECT * FROM centresportif420.personne WHERE codebarre='" + Server.HtmlEncode(((TextBox)(Login1.FindControl("UserName"))).Text) + "' AND motdepasse='" + Server.HtmlEncode(((TextBox)(Login1.FindControl("Password"))).Text) + "'";
                cmd      = new MySql.Data.MySqlClient.MySqlCommand(queryStr, cn);
                reader   = cmd.ExecuteReader();
                name     = "";
                while (reader.HasRows && reader.Read())
                {
                    name                  = reader.GetString(reader.GetOrdinal("nom"));
                    role                  = reader.GetString(reader.GetOrdinal("role"));
                    idpersonne            = reader.GetString(reader.GetOrdinal("idpersonne"));
                    Session["idpersonne"] = idpersonne;
                    Session["urole"]      = role;
                }
                if (reader.HasRows)
                {
                    Session["uname"]      = name;
                    Response.BufferOutput = true;
                    Response.Redirect("~/Account/Membre.aspx", false);
                    FormsAuthentication.SetAuthCookie(Server.HtmlEncode(((TextBox)(Login1.FindControl("UserName"))).Text), true);
                }
                else
                {
                    Response.Redirect("~/Account/Login.aspx", false);
                }
                reader.Close();
                cn.Close();
            }
        }