/**
  * returns Name of the newsletter who has id = $id
  * 
  * @param int $id
  * @param bool $forceCreate : if newsletter not exists create it
  * 
  * @return string
  */
 function getNewsletterName($id, $forceCreate = false)
 {
     if (!isset($this->a_newsletters)) {
         $this->loadNewsletter();
     }
     if (!isset($this->a_newsletters[$id]) && $forceCreate) {
         // If not exists, and force create : create Newsletter
         $confSite = new SiteConfigDb();
         if (defined("NEWSLETTER_CREATE_NAME")) {
             $confSite->createNewsletter($id, NEWSLETTER_CREATE_NAME . $id, $this->id);
         } else {
             $confSite->createNewsletter($id, 'Newsletter : ' . $id, $this->id);
         }
         // Reload Newsletter
         $this->loadNewsletter();
     }
     return isset($this->a_newsletters[$id]) ? $this->a_newsletters[$id] : false;
 }