Who’s Online

OK I am trying to inclued a who's online part in my website following this tutorial.  http://www.2enetworx.com/dev/samples/memwhoson.asp

My question is even though the user logs in it still shows Guest-0000.  How can I make it so it actually reads the username of the person that logs in.  I am using a session variable called "Session("userID")" .  When I look at the global.asa it seems like it is reading cookies.  Can someone kind of explain this to me so I can move in the write direction.

Thanks