public void LayDuLieuLenComboBox_DK_DAY(ComboBox cmb, string maday)
{
NguoiDungData hd = new NguoiDungData();
cmb.DataSource = hd.LayDSNguoiDung_DK_DAY(maday);
cmb.DisplayMember = "TENPHG";
cmb.ValueMember = "MAPHG";
}