correct formation of the session data for a plugin

[stardotstar]

I am hacking together a plugin to get the portal page to display properly as a location - rather than location unknown in the who is online page and I can't form the URL properly since I suspect it has changed since the original hack was written.

I have this

    $userinfo['where'] = '<a href="/forum/welcome.php?' . $vbulletin->session->vars['sessionurl'].'">Portal</a>';

and it returns a malformed url - I suspect that I need the vbulletin 3.8.2 formation of

$vbulletin->session->vars['sessionurl']

is that right? and can anyone assist me please?

Thanks in (vb)advance guys!