function mtime($time=NULL){    $text ="";        $times = NULL==$time || $time==time() ? $time : intval($time);    $t = time()-$times;    if($t==0){        $text="刚刚";    }elseif ($t<60) {        $text=$t."秒前";    }elseif ($t<3600) {        $text=floor($t/60)."分钟之前";    }elseif ($t<60*60*24) {        $text=floor($t/3600)."小时之前";    }elseif ($t<60*60*24*3) {        $text=floor($text/60*60*24)==1?"昨天".date("H:i",$time):"前天".date("H:i",$time);    }elseif ($t<60*60*24*30) {        $text = date('m月d日 H:i',$times);//一个月内    }elseif ($t<60*60*24*30*365) {//一年内        $text = date("m月d日",$times);    }else{//一年前        $text = date("Y年前",$times);    }    return $text;}