public function Form() { $form = parent::Form(); if ($this->VariableAmount) { $form->setSaveableFields(array("UnitPrice")); $form->Fields()->push($giftamount = new CurrencyField("UnitPrice", "Amount", $this->BasePrice)); $giftamount->setForm($form); } $form->setValidator($validator = new GiftVoucherFormValidator(array("Quantity", "UnitPrice"))); return $form; }