[Grml] grml-live, specifying GRML_LIVE_SOURCES

Hi,

Is it possible to *add to* current GRML_LIVE_SOURCES setting?

I tried,

GRML_LIVE_SOURCES="$GRML_LIVE_SOURCES # debian multimedia deb http://www.debian-multimedia.org sid main non-free . . . "

but got

/etc/grml/grml-live.local: line 29: GRML_LIVE_SOURCES: unbound variable

then I realized that the grml-live.local should be in python syntax, which I don't know.

Please help. Thanks