private void dataGridViewHoadonbanhang_DoubleClick(object sender, EventArgs e)
{
Form formSua = new BanHang(Convert.ToInt32(buttonSua.Tag));
formSua.ShowDialog();
XemHoadonbanhang_Load(sender, e);
}
private void taoHoaDonToolStripMenuItem_Click(object sender, EventArgs e)
{
Form f = findOpenedForm("BanHang");
if (f == null)
{
f = new BanHang();
f.MdiParent = this;
}
f.Show();
f.Activate();
}