Как прописать в ajax/freedback.php значение выбранное в календаре?

<td>
        <script type="text/javascript" src="/engine/skins/calendar.js"></script>
        <link rel="stylesheet" type="text/css" media="all" href="/engine/skins/calendar-blue.css" />
        <input name="calendar" id="calendar" type="text" />
        <img src="/engine/skins/images/img.gif" id="calendar_c" style="cursor: pointer; border: 0pt none;" title="Выбор даты с помощью календаря" align="absmiddle" />
        <script type="text/javascript">
            Calendar.setup({
                inputField     :    "calendar",     // id of the input field
                ifFormat       :    "%d.%m.%Y",      // format of the input field
                button         :    "calendar_c",  // trigger for the calendar (button ID)
                align          :    "Br",           // alignment 
                timeFormat     :    "24",
                showsTime      :    true,
                singleClick    :    true
            });
        </script>
</td>

        $recip   = intval( $_POST['recip'] );

        $calendar = $_POST['calendar'];

            $row['template'] = str_replace( "{%text%}", $message, $row['template'] );

            $row['template'] = str_replace( "{%calendar%}", $calendar, $row['template'] );

Дата исполнения: {%calendar%}