private function addTransactionElement($amount, $type, $options)
    {

        if ($type == 'PreAuth' || $type == 'Auth') {
            $this->xml .= <<<XML
 <Transaction>
 <Type DataType="String">{$type}</Type>
 <CurrentTotals>
 <Totals>
 <Total DataType="Money" Currency="{$this->currency_lookup(self::$default_currency)}">{$amount}</Total>
 </Totals>
 </CurrentTotals>
 </Transaction>
XML;
        } elseif ($type == 'PostAuth' || $type == 'Void') {
            $this->xml .= <<<XML
 <Transaction>
 <Type DataType="String">{$type}</Type>
 <Id DataType="String">{$options['authorization']}</Id>
 <CurrentTotals>
 <Totals>
 <Total DataType="Money" Currency="{$this->currency_lookup(self::$default_currency)}">{$amount}</Total>
 </Totals>
 </CurrentTotals>
 </Transaction>
XML;
        }
    }