private void mh_createBTN_Click(object sender, EventArgs e)
{
hangValue = 0;
TaoMatHang_Form form = new TaoMatHang_Form();
form.Show();
}
private void mh_editBTN_Click(object sender, EventArgs e)
{
hangValue = 1;
maHang = getMaHang();
TaoMatHang_Form form = new TaoMatHang_Form();
form.Show();
}