MySQL错误:'；按时间戳排序desc限制1'；在第5行

我正在尝试在MRBS日历中运行罗兰·卡森的脚本"showcalendar.php"几天。我在数据库中遇到了一些错误，但现在被这些错误卡住了：

"您的SQL语法有错误；请查看与您的MySQL服务器版本对应的手册，了解在第5行接近‘按时间戳排序desc limit 1’的地方使用的正确语法">

我使用MRBS 1.4.11，Apache/2.2.16(Debian(，MySQL客户端版本：5.1.66。我发现了这个主题：从mysql-mrbs日历显示今天的预订还查看了上的一些信息http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_timestamp并进行了gogol研究但没有进展。请你帮我或给我正确方向的建议好吗？非常感谢您的时间和精力：(

$conn = mysql_connect($mysql_host, $mysql_user, $mysql_pass)
or die(mysql_error());
mysql_select_db("mrbs", $conn)  or die(mysql_error());

$get_entries = "select timestamp
from $bookings
order by timestamp desc
limit 1
"
;
$entries_result = mysql_query($get_entries) or die(mysql_error());
$data_row = mysql_fetch_object($entries_result);
$last_changed = $data_row->timestamp;

$get_rooms = "select *
from $rooms
order by id
"
;
$rooms_result = mysql_query($get_rooms) or die(mysql_error());
$n_rooms = mysql_num_rows($rooms_result);
$n_cols = $n_rooms + 1;

$booking_block = "<TABLE align=center BORDER=1 CELLPADDING=5>'n";
$booking_block .= "<tr><td colspan=".$n_cols.">";
$booking_block .= "Room bookings for week beginning ";
$booking_block .= $startingDateArray['mday']." ";
$booking_block .= $startingDateArray['month']." ";
$booking_block .= $startingDateArray['year']." ";
$booking_block .= "(Last change to any booking was made ";
$booking_block .= $last_changed;
$booking_block .= ")</td></tr>'n";
$booking_block .= "<tr><td align=right>".$startYear."</td>'n";

while ($rooms = mysql_fetch_array($rooms_result, MYSQL_ASSOC))
{
$booking_block .= "<td>";
$booking_block .= $rooms['room_name'];
$booking_block .= "</td>";
}
$booking_block .= "</tr>'n";

for ($day_number = 0; $day_number <= 6; $day_number++)
{
$booking_block .= "<tr>'n";
$booking_block .= "<td align=right valign=top>";
$endOfDay = $theTimestamp + ONE_DAY;
$theDateArray = getdate($theTimestamp);
if ($theDateArray['year'] != $startYear)
{
    $startYear = $theDateArray['year'];
    $booking_block .= $startYear."<br>";
}
$booking_block .= date("D d M", $theTimestamp)."</td>'n";

for ($room_number = 1; $room_number <= $n_rooms; $room_number++)
{
    $get_bookings = "select *
        from $bookings
        where start_time >= $theTimestamp
        and start_time <= $endOfDay
        and room_id = $room_number
        order by start_time
        "
        ;
    $bookings_result = mysql_query($get_bookings) or die(mysql_error());
    $booking_block .= "<td valign=top>";
    if (mysql_num_rows($bookings_result) > 0)
    {
        while ($booking_entry = mysql_fetch_array($bookings_result, MYSQL_ASSOC))
        {
            $booking_block .= date("H:i", $booking_entry['start_time']);
            $booking_block .= "-";
            $booking_block .= date("H:i", $booking_entry['end_time']);
            $booking_block .= " ";
            $booking_block .= $booking_entry['name'];
            $booking_block .= "<br>'n";
        }
    }
    else
    {
        $booking_block .= "<br>";
    }
    $booking_block .= "</td>";
}
$booking_block .= "</tr>'n";
$theTimestamp = $theTimestamp + ONE_DAY;
}

$booking_block .= "<tr><td colspan=".$n_cols." align=right>";
$booking_block .= "This web page rendered at ";
$booking_block .= sprintf("%02d:%02d:%02d",
                        $nowArray['hours'],
                        $nowArray['minutes'],
                        $nowArray['seconds']);
$booking_block .= " on ";
$booking_block .= $nowArray['mday']." ";
$booking_block .= $nowArray['month']." ";
$booking_block .= $nowArray['year']." ";

$booking_block .= "</table>'n";