$amount = $form->{"amount_$i"} - $tax;
$form->{"amount_$i"} = $form->round_amount($amount, 2);
$diff += $amount - $form->{"amount_$i"};
$form->{"tax_$i"} = $form->round_amount($tax, 2);
$form->{netamount} += $form->{"amount_$i"};
} else {
$amount = $form->{"amount_$i"} - $tax;
$form->{"amount_$i"} = $form->round_amount($amount, 2);
$diff += $amount - $form->{"amount_$i"};
$form->{"tax_$i"} = $form->round_amount($tax, 2);
$form->{netamount} += $form->{"amount_$i"};
} else {