logon and logoff events

hi to everybody,I want yo know that how to track the logon and logoff events of my clients having 2000 professional and my Dc is 2003 server.I was tried by giving the success and failure audit in domain security policy.But that has given proper result.Pls help me.And i was posted this same in the forum question but there is no response and its going to be delete after a day automatically.