Adobe Lifecycle Designer - Submit to URL - suppress response/custom response

Adobe Lifecycle Designer - Submit to URL - suppress response/custom response

I've a very specific question regarding a form I made with Adobe Lifecycle
Designer. The user is able to fill out the form and hit the submit button
which sends the whole PDF to a HTTP-WebService. The whole process works
really well, except that I found no way to suppress the services response
or to customize it.
What's happening exactly?
Because of the nature of a WebService my servlet will alaways respond
(e.g. HTTP 1.1 / 200 success), this response triggers the Adobe Reader to
open a popup (which wants to open up the browser):
Image: http://i42.tinypic.com/2j35z60.png
What I really would like to do is get the answer of the WebService and
open up a custom popup like "Transfer successfull, you may dance now!".
Thanks a lot for your input, Wolfgang