protected function _getFieldDefaultValue($fieldName)
    {
        $metaData = $this->_getAllFields();
        foreach ($metaData as $metaInfo) {
            if (strcasecmp($metaInfo->name, $fieldName) == 0) {
                return property_exists($metaInfo, 'default_value') ? $metaInfo->default_value : null;
            }
        }

        return false;
    }