adding users to my "currently active users" list

[DionDev]

i just got back into vbulletin

now i am currently working on a mod

basically, i want this mod to select 50 random users from the DB, and add them to the "currently active users" list so that people visiting my forum see that its busy.

i wrote some code, but so far, its not populating the "currently active users" list on the homepage, but it is showing them in the online.php page.

heres my code:

mysql_query("insert into `session` (`sessionhash`, `userid`, `lastactivity`) values ('".md5(uniqid(microtime(), true))."', '$fuid', '".time()."')") or die(mysql_error());

$fuid comes from an array of 50 member userid's selected via a mysql query from the `user` table.

what am i missing?