private void loadcombobox()
        {
            DataTable dt = new DataTable();

            dtbus = new LapDonThuocBUS();
            dt    = dtbus.loadPKtoCombobox();
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                comboBox_mapk.Items.Add(dt.Rows[i][0].ToString());
            }
            ////

            LapDonThuocBUS dtbus1 = new LapDonThuocBUS();
            DataTable      dt1    = new DataTable();

            dtbus1 = new LapDonThuocBUS();
            dt1    = dtbus1.loadThuoctoCombobox();


            for (int i = 0; i < dt1.Rows.Count; i++)
            {
                comboBox_Loaithuoc.Items.Add("(" + dt1.Rows[i][0] + ")\t" + dt1.Rows[i][1].ToString());
            }
            LapDonThuocBUS dtbus2 = new LapDonThuocBUS();
            DataTable      dt2    = new DataTable();

            dtbus2 = new LapDonThuocBUS();
            dt2    = dtbus2.loadCDtoCombobox();
            for (int i = 0; i < dt2.Rows.Count; i++)
            {
                comboBox_cachdung.Items.Add("(" + dt2.Rows[i][0] + ")\t" + dt2.Rows[i][1].ToString());
            }
        }
        private void load_datagridview()
        {
            dtbus = new LapDonThuocBUS();
            List <LapDonThuocDTO> list = dtbus.select(comboBox_mapk.Text);

            loadDonThuoc(list);
        }