private void LoadcmbBN()
{
BenhNhanCtrl bnctr = new BenhNhanCtrl();
cmbMaBN.DataSource = bnctr.GetData();
cmbMaBN.DisplayMember = "MaBN";
txtTenBN.DataBindings.Clear();
txtTenBN.DataBindings.Add("Text", cmbMaBN.DataSource, "HoTen");
cmbMaBN.ValueMember = "MaBN";
}
