private void cmbNgachCongChuc_KeyDown(object sender, KeyEventArgs e) { if (e.KeyCode == Keys.F5) { frmDM_NgachCongChuc frm = new frmDM_NgachCongChuc(null, this); frm.ShowDialog(); if (IDNS_NgachCongChuc > 0) { cmbNgachCongChuc.Properties.DataSource = LoadNgachCongChuc(); cmbNgachCongChuc.EditValue = IDNS_NgachCongChuc; } } if (e.KeyCode == Keys.Delete) { cmbNgachCongChuc.EditValue = null; } }