The powerbook lap top was going into sleep mode automatically after several minutes of un use. I don't know if I accidentally changed something. How do I get it to go into sleep mode when it isn't being used?
Go to System Preferences usually in the dock, can also be found in the Applications folder), go to Energy Saver and if you can't see any sliders to do with sleep, click Show Details.
Apple Powerbooks are intelligent little things and can automatically change these settings based on whether they are plugged in or not.