$invoicing = CRM_Utils_Array::value('invoicing', $invoiceSettings);
$this->assign('invoicing', $invoicing);
if ($invoicing && isset($values['tax_amount'])) {
$invoicing = CRM_Utils_Array::value('invoicing', $invoiceSettings);
$this->assign('invoicing', $invoicing);
if ($invoicing && isset($values['tax_amount'])) {