Regarding exception handling in webdynpro

Dear frds..

I am using webservice for webdynpro application.,,,

when i call a particular method of webservice in webdynpro i get o/ps but when i give wrong outputs the webservice exception is shown in webdynpro at the bottom

I dont wanna to display the exception mesage doen the bottom,

Instead of dispalying the exception message, i want to dispaly some other things like confirmation box or dialog box..

How to catch exceptions in webdynpro?

if use try catch finally block in webdynpro,

and in catch block i kept messaeg of popup confiramtion box, it is not been displayed....

Thanks in advance

Shravan