How to setup Firefox to use arts?

[Marcelo Magno T. Sales]

Hi, people

In FC4, how to setup Firefox to play sounds using arts, instead of
accessing /dev/dsp directly?
I've googled around and read this problem should be solved including
'FIREFOX_DSP="arts"' in /etc/mozilla-firefox/mozilla-firefoxrc or in
~/.mozilla/firefox/rc. However, it did not work in FC4...
Any clues?

Thanks,

Marcelo