I just bought (5/30/2000) a brand new 2000 SLK 230 (to complement my 300E of course

and I was wondering if anyone knew how to use those three buttons on the roof panel... they are supposed to be programmable garage door openers??? or something like that. Since it is a 2000 and not a 2001 model, the dealership is ordering my manuals at this time. So I can't figure out how to use them. If you push any of the buttons the light lights up, but that's it.. any help would be appreciated!
Thanks,
Jay Huang
1987 300E
2000 SLK 230 Sport