Audit a specific user logins to network

I need to be able to audit one specific user’s login to our network and record the dates and times that they log into the network and also when they logout. We have a Windows 2003 domain with active directory. Is there a easy way to do this for a specific user only? (I read the TechRepublic article on doing it for all users via a Group Policy) Is there a third party utility (free or cheap to buy) to do this?