private void btn_send_message_Click(object sender, EventArgs e) { SendEmail sendMassage = new SendEmail(); sendMassage.Body = txt_Body.Text; sendMassage.Subject = txt_Body.Text; if (ModelState.IsValid(sendMassage)) { UserRequests.SendMessage(GlobalProp.CurrentUser.UserId, sendMassage); } else { foreach (var item in ModelState.Results) { errorProvider1.SetError(Controls["txt_" + item.MemberNames.ToList()[0]], item.ErrorMessage); } } }