Firing event when validation failed in JSF2.0??

Hi,

I have the following requirement:

A user enters a date in a textfield. If the date is incorrect or empty
the following inputfields should be disabled via ajax and an error
message is displayed.

The problem is that I cannot send any events when the
conversion/validation fails (invoke application and value changeevents
are not fired).

What I need is a validationFailedEvent. Is this possible with any ajax
library or JSF2.0??



Greetings
Stefan