private void btn_Sua_Click(object sender, EventArgs e)
 {
     if (dtGridThucDon.CurrentRow.Cells[1].Value == null || dtGridThucDon.CurrentRow.Cells[1].Value.ToString() == String.Empty)
     {
         MessageBox.Show("Vui lòng chọn đồ uống cần chỉnh sửa");
     }
     else
     {
         try
         {
             int maMon = Convert.ToInt32(dtGridThucDon.CurrentRow.Cells[1].Value.ToString());
             Form_ThemDoUongMoi frm = new Form_ThemDoUongMoi(maMon);
             frm.Show();
         }
         catch (Exception ex)
         {
             MessageBox.Show("Mã món không hợp lệ");
         }
     }
 }
        private void btn_Them_Click(object sender, EventArgs e)
        {
            Form_ThemDoUongMoi frm = new Form_ThemDoUongMoi();

            frm.Show();
        }