Vreemd! MySQL-update werkt niet zonder fout

Het onderstaande is mijn code om een ​​account aan te maken in mijn project. De code werkt perfect tot Response.Write (iduser) maar de opdracht UPDATE werkt niet. Geen fout gevonden met uitzondering, maar MySQL's record is niet bijgewerkt.

    try
                {

                    string pet1 = "[email protected]";
                    string MyConString = "DRIVER={MySQL ODBC 3.51 Driver};" + "SERVER=localhost;" + "DATABASE=newtest;" + "UID=root;" + "PASSWORD=**********;" + "OPTION=3";
                    OdbcConnection MyConnection = new OdbcConnection(MyConString);
                    OdbcCommand cmd = new OdbcCommand("Select id_user from awm_accounts where email=?", MyConnection);
                    cmd.Parameters.Add("@val1", OdbcType.VarChar, 255).Value = pet1;
                    MyConnection.Open();
                    OdbcDataReader dr = cmd.ExecuteReader();
                    if (dr.HasRows == false)
                    {
                        throw new Exception();
                    }
                    if (dr.Read())
                    {
                        int iduser = Convert.ToInt32(dr[0].ToString());
                        Account acct = new Account();
                        acct.Email = username.Text + domain.Text;
                        acct.MailIncomingLogin = username.Text + domain.Text;
                        acct.MailIncomingHost = "imap." + DropDownList1.SelectedValue;
                        acct.MailIncomingPassword = password.Text;
                        acct.MailIncomingPort = 993;
                        acct.MailOutgoingHost = "smtp." + DropDownList1.SelectedValue;
                        acct.MailOutgoingPort = 465;
                        acct.MailIncomingProtocol = IncomingMailProtocol.Imap4;
                        acct.MailOutgoingAuthentication = true;
                        acct.DefaultAccount = false;
                        acct.IDUser = 1;
                        integr.CreateUserFromAccount(acct);
                        Response.Write(iduser);
                        if (!IsPostBack)
                        {
                            cmd = new OdbcCommand("UPDATE awm_accounts SET id_user=? WHERE email=? ", MyConnection);
                            cmd.Parameters.Add("@tb_nickname", OdbcType.Int, 11).Value = iduser;
                            cmd.Parameters.Add("@tb_fullname", OdbcType.VarChar, 255).Value = username.Text + domain.Text;
cmd.ExecuteNonQuery();
                        }
                    }
                    MyConnection.Close();
                }
            catch (Exception exp)
            {
                Response.Write(exp);
            }