Change Username, update non-vb table with plugin?

[bigtime]

Hello,

I'm working on integrating another script to use the same user table as vb. I also need the user table in the other script to have the same usernames as vb.

So, when editing a username from the vb admin, I need to also update my other table.

I tried this in the userdata_update_username hook location but it didn't work and resulted in a blank page:

PHP Code:

$db->query_write("UPDATE review_users
    SET username='$username' WHERE username='$username'"); 


I'm guessing that by the time I'm I'm trying to access $username it has already changed to the new edited name?

Please put me in the right direction....

Thanks,

Tim