Determining Concurrent Users that have logged into a shared access database

I'm having trouble finding the number of users that have logged into a shared access database. Could someone help me find the number of users that have logged into the access database using VB?

Thanks

I use a table to store the user name and date/time when they login and log out of the database. I have a form that displays this information in a list box and I can readily see who is logged in and who is not at any time. I also use this information to establish frequency of the users and how long they are logged into the database. It's fairly simple and works for me.

lwells