Get behaviour id of the ajax calender extender

 <script type="text/javascript">
        function onCalendarShown2(sender){ 
            //sender is the shown extender self.
            //var cal = $find(sender._id);
            //cal._visibleDate = target.date;
            //cal.set_selectedDate(target.date);
            //cal._switchMonth(target.date);
            var CalendarBehavior = $find(sender._id);
            //here hide this 
           // CalendarBehavior.hide();
            //here show this 
            CalendarBehavior.show();
        }

    </script>

http://forums.asp.net/t/1984233.aspx