Firefox - How to play wmv files?

I'm running FC4 i386. I've installed xine, mplayer, kaffeine, and totem
and the win32 codecs. I can get these programs to play wmv files. How do
I get Firefox to play them? For example, if I go to www.cnn.com and
click on video, it complains about a plugin. I go to edit/preferences in
Firefox but it won't let me tell it to use xine or whatever. Any ideas
on how to get this to work?

Rick B.