is_ok example

$this->ERROR = "POP3 connect: " . _("Error ") . "[$errno] [$errstr]";
            unset($this->FP);
            return false;
        }

        socket_set_blocking($fp,-1);
        $this->update_timer();
        $reply = fgets($fp,$this->BUFFER);
        $reply = $this->strip_clf($reply);
        if($this->DEBUG)
            error_log("POP3 SEND [connect: $server] GOT [$reply]",0);
        if(!$this->is_ok($reply)) {
            $this->ERROR = "POP3 connect: " . _("Error ") . "[$reply]";
            unset($this->FP);
            return false;
        }
        $this->FP = $fp;
        $this->BANNER = $this->parse_banner($reply);
        return true;
    }

    function user ($user = "") {
        // Sends the USER command, returns true or false