checking to see if the user is logged in

[brookelyn]

I have chat somewhat integrated with my board, however when I upgraded to vB2 today, things no longer worked. The username variable had changed, I fixed that and now users are able to login as their username on the board, however if they ARENT logged in, it logs them in as "Unregistered" - For some reason it is not checking to see if they are logged in or not so it's giving people access that shouldn't have access - Anyway, below is the code I am using the check whether or not they are logged in - does anyone know offhand what the problem could be?

<? if ($bbuserinfo[username] != "" ){ ?>