private void refresh_form() { m_txt_ma_dv.Text = ""; m_txt_ma_dv.BackColor = Color.White; //m_lbl_kiem_tra_ma_dv.Visible = false; m_txt_ten_dv.Text = ""; //m_sle_loai_dv.EditValue = null; m_sle_chon_dv_cap_tren.EditValue = null; }