Close PopupControlExtender using javascript

Sometime you may need to close the PopupControlExtender programmatically, here is how you can do it.

You can use "AjaxControlToolkit.PopupControlBehavior.__VisiblePopup.hidePopup()" to close the popup. e.g.-
<a onclick="AjaxControlToolkit.PopupControlBehavior.__VisiblePopup.hidePopup(); return false;"> Close </a>