private void clearData()
{
txtmanv.Text = nvMod.SinhMaTuDong("NHANVIEN", "MANV", "NV00");
txttennv.Text = "";
txtdiachi.Text = "";
txtsdt.Text = "";
dtpns.Value = DateTime.Now.Date;
pbanhnv.Image = null;
cmbgt.Text = "Nam";
loadCMB();
}