尽管脚本管理器，Ajax日历扩展器不可用？

I've got a calendar extender on one page, and it works fine. Placed in panel with script manager, no problems. On another aspx page, however, using the same format, despite my script manager in the same position, the calendar extender is unavailable. Error message reports that the Calendar Extender is not a known element. Why? Code below for both instances.I've got a calendar extender on one page, and i