Log on 2 different domains from laptop

I have two different domains i need to be able to log onto. I have my office domain and my onsite project domain. I need to be able to switch back and forth from one to the other without reseting my domain in windows every time. I would like to be able to log off on, then select the other domain and log on. The laptop is running windows 2000 and both servers are 2000 Is this possible? If not what would be my best approach because I can’t surf or ip into the other domain without getting “There are currently no logon servers available to service this request”. I can ping the other computers. I also can’t map the shared folders as network drives. Please help ASAP. Thank you