$sPath = "./files/" . $userid . "/";

if (chdir($sPath)) {

    //   $dirs = glob('*', GLOB_ONLYDIR);

       $dirs = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($sPath), RecursiveIteratorIterator::SELF_FIRST);

       foreach($dirs as $val){
          echo '<option value="'.$val.'">'.$val."</option>\n";
       }
        } else {
       echo 'Changing directory failed.';
}