public static function DoCheckCalDAVServer($scheme, $host = null, $port = null, $username = null, $password = null, $path = null)
 {
     if ($scheme . "!" == intval($scheme) . "!") {
         $scheme = intval($scheme);
         if ($scheme <= 0) {
             return false;
         }
         $arConnection = CDavConnection::GetById($scheme);
         if (!is_array($arConnection)) {
             return false;
         }
         $scheme = $arConnection["SERVER_SCHEME"];
         $host = $arConnection["SERVER_HOST"];
         $port = $arConnection["SERVER_PORT"];
         $username = $arConnection["SERVER_USERNAME"];
         $password = $arConnection["SERVER_PASSWORD"];
         $path = $arConnection["SERVER_PATH"];
     }
     $client = new CDavGroupdavClientCalendar($scheme, $host, $port, $username, $password);
     if (CDav::UseProxy()) {
         $arProxy = CDav::GetProxySettings();
         $client->SetProxy($arProxy["PROXY_SCHEME"], $arProxy["PROXY_HOST"], $arProxy["PROXY_PORT"], $arProxy["PROXY_USERNAME"], $arProxy["PROXY_PASSWORD"]);
     }
     return $client->CheckWebdavServer($path);
 }