/**
  * sets the display currency for the cart.
  * @param String $currencyCode
  * @return Boolean
  **/
 public function setCurrency($currencyCode)
 {
     $currency = EcommerceCurrency::get_one_from_code($currencyCode);
     if ($currency) {
         if ($this->currentOrder()->MemberID) {
             $member = $this->currentOrder()->Member();
             if ($member && $member->exists()) {
                 $member->SetPreferredCurrency($currency);
             }
         }
         $this->currentOrder()->UpdateCurrency($currency);
         $msg = _t("Order.CURRENCYUPDATED", "Currency updated.");
         $this->addMessage($msg, 'good');
         return true;
     } else {
         $msg = _t("Order.CURRENCYCOULDNOTBEUPDATED", "Currency could not be updated.");
         $this->addMessage($msg, 'bad');
         return false;
     }
 }