How to propogate the error message on the layout screen

Hi,

I have a FM call in the OnAction of a button, if that FM returns an exception, the system throws an exception

raise exception type cx_wd_no_handler

exporting

textid = cx_wd_no_handler=>kind_old

old_exception = `NO_ZIP_CODE`.

But I want the long text of this exception to be shown on the screen when I run the Web Dynpro Application...How to go about this??

Thanks,

Deepti Kaza.