Actually the XHTMLExtension class is probably a bad example to follow, as it is not even a valid extension. There 4 things that need changed in this class to allow it to be used as an extension:
1) Must implement ISerializable
2) Change the namespace to "http://jabber.org/protocol/xhtml-im" (I was only testing this with a GAIM client, so this might not be necessary)
3) Support a default parameter-less constructor: public function XHTMLExtension(parent:XMLNode=null)
4) Implement a serialize and deserialize method
chandan - You should take a look at the RegisterExtension under org.jivesoftware.xiff.data.register. I used this as the starting point to implementing several extensions successfully.
