/**
  * Attributes options
  *
  * @return Smile_VirtualCategories_Model_Rule_Condition_Product
  */
 protected function _prepareValueOptions()
 {
     $specialAttributes = array('in_stock', 'has_image', 'has_discount', 'is_new');
     if (in_array($this->getAttribute(), $specialAttributes)) {
         $this->setData('value_select_options', array(array('value' => '1', 'label' => Mage::helper('adminhtml')->__('Yes'))));
         $this->setData('value_option', array('1' => Mage::helper('adminhtml')->__('Yes')));
     } else {
         parent::_prepareValueOptions();
     }
     return $this;
 }