Hello all, I have been using the ModalPopupExtender as a way of catching errors and displaying them to users. This includes business rule violations that I catch. This all works fine as long as I can write the if statement to trap the error. However this does not work in the case of un-handled exceptions. I have recently found out that un-handled ajax exceptions can be dealt with using the AsyncPostBackError event. So what I have been trying to do is deal with the error using the AsyncPostBackError event and this display a custom message using the ModalPopupExtender. What I'm finding now is that the ModalPopupExtender does not work after an un- handled ajax exception. Apparently the processing of the page stops after the error so I can't call the UpdatePanel.Update() and ModalPopupExtender.Show() methods. I would really like to be able to re-use the ModalPopupExtender for all error messages. Can anyone tell me how I might solve this problem? Thanks