private void register_SelectedIndexChanged(object sender, EventArgs e)
{
if (register.SelectedTab.Text == tabBrg.Text)
{
Barang brg = new Barang();
idBrg.Text = brg.showIdBrg();
}
else if (register.SelectedTab.Text == tabCust.Text)
{
Customer cust = new Customer();
idCust.Text = cust.showIdCust();
}
else if (register.SelectedTab.Text == tabSup.Text)
{
Supplier sup = new Supplier();
idSup.Text = sup.showIdSup();
}
}