<script> as handler for XML events

Jonas,

I'm developing a Mozilla extension implementing XHTML+Voice, or X+V (see 
http://www.w3.org/TR/xhtml+voice/ and 
http://www.voicexml.org/specs/multimodal/x+v/12/) The X+V profile pulls 
in VoiceXML <form> and makes it a handler for XML events. However, to 
make a multimodal application truly interesting, the document author 
needs the ability to respond to the XML events emitted by VoiceXML. 
Opera and NetFront have implemented <script> as a handler by allowing it 
to be specified in the XML events <listener> element, without otherwise 
affecting the behavior of <script> (it still executes on page load, for 
example.) This approach is used in examples in the XML spec but is not 
normative. There was some discussion of including it in the Mozilla XML 
events implementation 
(https://bugzilla.mozilla.org/show_bug.cgi?id=164482) .

What are the options to implement this behavior in Mozilla?

chris