Exception with A4J

[atimo]

I have 2 questions, can anyone help-me with it?
1) How can I take a message from the exception throwed by the server on a ajax request? for example a new BusinessException("the error is ...."), I wanted get this message to show to user with javascript.
2) How can I fix it, when the server throws a exception, with firefox the oncomplete method doesnt execute, but with IE6 it executes.

thank you for help.

[atimo]

I'd like if there is a way to resolve exceptions like dwr

http://getahead.org/dwr/other/errors


Is there any way to do it?