login on not-vb page

hi all,
i wanna do this: when a user login on my homepage he is directly logged to the forum too.
i've inserted this part of code in my login.php file in my root dir:

PHP Code:

if ($user['cookieuser']==1) {
   vbsetcookie("bbuserid",$czuserid);
   vbsetcookie("bbpassword",$_POST['login_pw']);
   }
            
$DB_site->query("DELETE FROM session WHERE sessionhash='".addslashes($session[dbsessionhash])."'");

$session['sessionhash']=md5(uniqid(microtime()));
$session['dbsessionhash']=$session['sessionhash'];
$DB_site->query("INSERT INTO session (sessionhash,userid,host,useragent,lastactivity,styleid) VALUES ('".addslashes($session['sessionhash'])."','".intval($userid)."','".addslashes($session['host'])."','".addslashes($session['useragent'])."','".time()."','$session[styleid]')");

vbsetcookie("sessionhash",$session['sessionhash'],0); 

but it doesn't work...
please someone help me

much thanks in advance.