Its like everytime ... I take the new version of SAP-ME-Development Guides, read about a new function, starting to smile because its sounds cool, try it and get annoyed because it doesn't work even the detailed examples!
WPMF-Guide, Page 33, Chapter 5.2.9 IFrame Plugins ...
The Plugins should implement the IFrameOnMessageListenerInterface but this Interface isn't available in the public-API. Shure I can drop the jar manualy in my extlib-folder, but why does SAP provide solutions and guides that aren't usable?!