private void btnTongLuong_Click(object sender, EventArgs e)
        {
            Luong temp = new Luong(txtMaNV.Text, txtLuong.Text, txtLuongThuong.Text, txtGhichu.Text, txtSNTC.Text, txtTongLuong.Text);

            ConnectDatabase.TongLuong_NV(temp);
            dgvLuong_CaNhan.DataSource = ConnectDatabase.GetAllLuong_NV();
        }