apt-get testing HELP please

[Bill Kalebaugh <billk@lvnworth.com>]

What do I have to put in sources.list to do an install from testing.
The command I want to use is:
 "apt-get -t testing install nvidia-glx nvidia-kernel-source 
nvidia-kernel-common"
Right now I get "E: Couldn't find package nvidia-glx"

Thanks Bill K