function checkUserIsOnline($userid){
		$online = false;
		$res = $GLOBALS['TYPO3_DB']->sql_query('SELECT DISTINCT ses_userid, username, name
				FROM fe_sessions LEFT JOIN fe_users ON (ses_userid=uid)
				WHERE ses_tstamp+3600 > unix_timestamp() OR is_online+3600 > unix_timestamp() and ses_userid='.$userid);
		while(false!==($row=$GLOBALS['TYPO3_DB']->sql_fetch_assoc($res))){
			if($row['ses_userid']==$userid)$online=true;
		}
		return $online;
	}