Post packingslip with multiple salesOrders using X++

Hi All,

I'm looking for some example code on how the post multiple orders on a packingslip (or invoice) using X++. I know how to post 1 order. Example:

SalesFormLetter letter=SalesFormLetter::construct(DocumentStatus::Invoice);
SalesTable sale = SalesTable::find('ORDR00000229');
;
    ttsBegin;
    letter.update(sale, systemDateGet(), SalesUpdate::PickingList, AccountOrder::None, true, true);
    ttsCommit;

But this is just one order. What if I want to post multiple orders at the same time ?

Thanks,
Gerard