Hi,

If the button raises a server side event and the event is not captured by AJAX, then the full page will be reloaded and the dialog will be automatically closed. If the event is captured by AJAX and the dialog is AJAX updated (for example, inside the CallbackPanel, then you will need to set the dialog's InitialState to Hiden in your code.

If the button does not raises a server side event, or the event is captured by AJAX but the dialog is not being AJAX updated, then you can call this method from JavaScript to close the dialog:

http://www.essentialobjects.com/doc/1/jsdoc.public.dialog.close.aspx

Note that none of the case has anything directly to do with whether you have a UserControl or not. However if you need to access the dialog from within your UserControl, then you must somehow expose the dialog control from the hosting page ---- this part is generic ASP.NET programming (how to access a control in parent page from a user control), so it's not covered by our tech support. You can search online for that if that's your case.

Thanks!