Is possible Open Proforma without close the form?

This to prevent the user from re-entering the info after making a mistake.

I try this in other button (Preview) in SalesEditLines Form and it shows it correctly, then close the proforma

pastedimage1555440929251v1.png

void clicked()
{

salesFormLetter.proforma(true);
salesFormLetter.printFormLetter(true);

salesFormLetter.run();

super();

}

Once I see that the information is correct, I close the proforma and click on OK for the invoice to be registered but it shows me this error.

Cannot edit a record in Sales order - update (SalesParmUpdate).
The values displayed in the form are not current, so an update or deletion cannot be made. To view the current values, on the Command menu, click Restore or press CTRL+F5.

Thanks in advance!