// $policy - 0 or 1: writeoff/return for IV, back order/cancel for DN
function write($policy=0) {
begin_transaction(); // prevents partial database changes in case of direct delivery/invoice
+ if ($this->reference != 'auto' && $this->trans_no == 0 && !is_new_reference($this->reference, $this->trans_type))
+ {
+ commit_transaction();
+ return -1;
+ }
if (count($this->src_docs) == 0 && ($this->trans_type == ST_SALESINVOICE || $this->trans_type == ST_CUSTDELIVERY)) {
// this is direct document - first add parent
$ref = $this->reference;