How do you get the interior lights to come on in a Pontiac Montana 03?

We had this same problem and found out through trial and error that there is a switch on the roof control panel (in our 2003 model) that apparently kills all lights in the cabin when the doors open. (Our young son had been playing with all the buttons in our "new" van one day without us knowing!) It is the button closest to the driver above the rearview mirror.