public void LoadNV() { TaiKhoan_DTO tk = new TaiKhoan_DTO(); tk.Username = tbxMaNV.Text; List <TaiKhoan_DTO> Ls_TK = TaiKhoan_BUS.List_TK(tk); foreach (var item in Ls_TK) { tbxMKOld.Text = ""; tbxTenNV.Text = item.TenNV; tbxChucVu.Text = item.Chucvu; } if (tbxChucVu.Text == "NhanVien") { textBox1.Enabled = false; textBox2.Enabled = false; button1.Enabled = false; } }