/**
  * 检查下一次检查unread的时间是否到达
  * @return bool
  */
 function _checkNextUnreadTime()
 {
     if (XWB_S_UID < 1) {
         return false;
     }
     $sess = XWB_Plugin::getUser();
     $nexttime = intval($sess->getInfo('xwb_nextunread_' . XWB_S_UID));
     //return true;
     return $nexttime == 0 || time() >= $nexttime;
 }