private function initServer()
 {
     include_once './Services/LDAP/classes/class.ilLDAPServer.php';
     if (!$_GET['ldap_server_id']) {
         $_GET['ldap_server_id'] = ilLDAPServer::_getFirstServer();
     }
     $this->server = new ilLDAPServer((int) $_GET['ldap_server_id']);
 }