Show numbers of online in navbar template

[rellect]

I want to show the number of online in the navbar template..
I create a plugin and use "global_bootstrap_init_start" hook.
this is the plugin :

global $vbulletin;

$newuserinfo = array(
'userid' => $vbulletin->userstats['newuserid'],
'username' => $vbulletin->userstats['newusername']
);

vB_Template::preRegister('navbar',array(
'totalonline' => $activemembers
));
In all forum pages it's work, but in CMS it's show 0..
Someone know what should I do?