# check if there is a vendor, invoice and due date
$form->isblank("transdate", $locale->text("Invoice Date missing!"));
$form->isblank("duedate", $locale->text("Due Date missing!"));
# check if there is a vendor, invoice and due date
$form->isblank("transdate", $locale->text("Invoice Date missing!"));
$form->isblank("duedate", $locale->text("Due Date missing!"));