private void btnAdd_Click(object sender, EventArgs e)
{
if (string.IsNullOrWhiteSpace(txtTenSP.Text) || string.IsNullOrWhiteSpace(txtDonVi.Text) || string.IsNullOrWhiteSpace(txtGiaBan.Text))
{
MessageBox.Show("Ban phai nhap day du thong tin");
return;
}
else
{
flag = 1;
product.AddProduct_Bus(getInfo(), dt);
clear();
}
}