static void PostpurchInvoice(Args _args)
{
purchformletter purchformletter;
purchtable purchtable;
;
purchformletter =
purchformletter::construct(DocumentStatus::PackingSlip,true);
purchtable.clear();
purchtable = purchtable::find(your purchase ID);
purchformletter.update(purchtable,'num',systemDateGet(),
purchUpdate::All,
AccountOrder::None,
false,
false);
}
using the same later you can post the invoice by replacing packing slip with invoice.