/**
  * Add config options in CMS site configuration section
  * 
  * @see DataObjectDecorator::updateCMSFields()
  */
 function updateCMSFields(&$fields)
 {
     // Show warning message
     if (!ClickBankManager::validate_required_modules()) {
         $fields->addFieldToTab("Root.ClickBank", new LiteralField("ClickBankWarningHeader", _t('ClickBank.MESSAGE_WARNINGMISSINGMODULE')));
     }
     $fields->addFieldToTab("Root.ClickBank", new LiteralField('ClickBankIPNTitle', _t('ClickBank.CONFIG_GENERAL_SETTINGS_SECTION_TITLE')));
     $fields->addFieldToTab("Root.ClickBank", new TextField('ClickBankID', _t('ClickBank.CONFIG_CLICKBANKID')));
     $fields->addFieldToTab("Root.ClickBank", new TextField('ClickBankSecretKey', _t('ClickBank.CONFIG_SECRETKEY')));
     $fields->addFieldToTab("Root.ClickBank", new TextField('ClickBankSkin', _t('ClickBank.CONFIG_SKINID')));
     $clickBankHolder = DataObject::get_one('ClickBankHolder');
     $site_ipn_url = '';
     if ($clickBankHolder) {
         $site_ipn_url = Director::absoluteURL('/clickbank/ipn');
     }
     $ipn_textfield = new ReadonlyField('ClickBankIpnUrl', _t('ClickBank.CONFIG_IPN_URL'), $site_ipn_url);
     $fields->addFieldToTab("Root.ClickBank", $ipn_textfield);
     $fields->addFieldToTab("Root.ClickBank", new LabelField('IpnUrlLabel', _t('ClickBank.CONFIG_IPN_URL_LABEL')));
     //$fields->addFieldToTab("Root.ClickBank", new LiteralField('ClickBankAPI', _t('ClickBank.CONFIG_API_SECTION_TITLE')));
     //$fields->addFieldToTab("Root.ClickBank", new TextField('ClickBankApiKey', _t('ClickBank.CONFIG_API_KEY')));
     //$fields->addFieldToTab("Root.ClickBank", new TextField('ClickBankDeveloperApiKey', _t('ClickBank.CONFIG_API_DEVELOPER_KEY')));
     //$fields->addFieldToTab("Root.ClickBank", new LiteralField('ClickBankSiteModeHeader', _t('ClickBank.CONFIG_SITE_MODE_SECTION_TITLE')));
     //$fields->addFieldToTab("Root.ClickBank", new CheckboxField('ClickBankTestMode', _t('ClickBank.CONFIG_SITE_MODE')));
 }