private void frmPhieuNhap_Load(object sender, EventArgs e)
{
KhoaDieuKhien();
cboCotTK.Text = "Mã Phiếu Nhập";
HienThiDuLieu("");
//lấy tt nv
cboMaNV.DataSource = bll.LayThongTinNV("");
cboMaNV.ValueMember = "MaNV";
cboMaNV.DisplayMember = "MaNV";
//lấy tt ncc
cboMaNCC.DataSource = bll.LayThongTinNCC("");
cboMaNCC.ValueMember = "MaNCC";
cboMaNCC.DisplayMember = "MaNCC";
}