function getDataServerRegistration()
 {
     if (is_file("/etc/elastix.key")) {
         $serverKey = file_get_contents("/etc/elastix.key");
     } else {
         $serverKey = "";
     }
     ini_set("soap.wsdl_cache_enabled", "0");
     $url_webservices = "https://webservice.elastix.org/modules/installations/webservice/registerWSDL.wsdl";
     try {
         $client = new SoapClient($url_webservices);
         $content = $client->getDataServerRegistration($serverKey);
         return $content;
     } catch (SoapFault $e) {
         return null;
     }
 }