function insertRows(RM_Extras_Row $extra, array $unitIDs)
{
$this->delete('extra_id=' . $extra->id);
//remove old values
if ($unitIDs[0] == 0) {
//all units
$extra->global = 1;
$extra->save();
return true;
} elseif ($extra->global == 1) {
$extra->global = 0;
$extra->save();
}
foreach ($unitIDs as $unitID) {
$this->createRow(array('extra_id' => $extra->id, 'unit_id' => $unitID))->save();
}
}