private void frm_load(object sender, EventArgs e)
        {
            //hienthi();
            nhanvienBLL pbll = new nhanvienBLL();

            dataGridView1.DataSource = pbll.hienthinhanvien();
            trangthai(false);
            btnluu.Enabled = false;
            btnhuy.Enabled = false;
        }
        private void btnxoa_Click(object sender, EventArgs e)
        {
            nhanvienBLL  nvBLL = new nhanvienBLL();
            DialogResult luu   = MessageBox.Show("Bạn chắc chắn xóa??", "Thông báo thêm mới", MessageBoxButtons.YesNo, MessageBoxIcon.Warning);

            if (luu == DialogResult.Yes)
            {
                nvBLL.xoa_nhanvien(int.Parse(txtmanv.Text));
                hienthi();
            }
        }
 private void btnluu_Click(object sender, EventArgs e)
 {
     trangthai(false);
     if (temp == 1)
     {
         nhanvienBLL nvBLL = new nhanvienBLL();
         nvBLL.them_nhanvien(txttennv.Text, travegioitinh(), dtngaysinh.Value, txtscm.Text, txtdiachi.Text, txtsdt.Text, dtngayvaolam.Value);
         hienthi();
     }
     else
     {
         nhanvienBLL nvBLL = new nhanvienBLL();
         nvBLL.sua_nhanvien(txttennv.Text, travegioitinh(), dtngaysinh.Value, txtscm.Text, txtdiachi.Text, txtsdt.Text, dtngayvaolam.Value, int.Parse(txtmanv.Text));
         hienthi();
     }
     btnluu.Enabled  = false;
     btnhuy.Enabled  = false;
     btnsua.Enabled  = true;
     btnthem.Enabled = true;
     btnxoa.Enabled  = true;
 }
        private void hienthi()
        {
            nhanvienBLL pbll = new nhanvienBLL();

            dataGridView1.DataSource = pbll.hienthinhanvien();
        }