Help with validating a PHP script... "unexpected $end"

[ngaming.net]

I'm no genius with PHP, this will probably be obvious to you at some point soon.

I've written a PHP script to perform a very specific function: find all users who have a session open on the site AND find if they have ticked a particular profile field as yes. I'm not really used to this (ColdFusion and .NET developer, the syntax is confusing me) so please help!

<?php

function get_onlinehosts($onlinehosts)
{
    global $vbulletin;
    $datecut = TIMENOW - $vbulletin->options['cookietimeout'];
    $onlinehosts = $vbulletin->db->query_first("SELECT * FROM " . TABLE_PREFIX .     "session 

WHERE userid = $userinfo[userid] AND lastactivity > $datecut AND     .userfield.field6 = 'yes'
    INNER JOIN " . TABLE_PREFIX . "userfield  ON(session.userid = userfield.userid));
  {
      return $onlinehosts;
  }
}
?>