Auto login user

[LunchBreak]

Hi I am doing a autologin for users who come from my site. When they come to vBulletin they are not asked for any credentials. I have the userid in my hand. So, this is how I am trying to log the user in.
$newuserid is the userid I already know.

$newsession->set('userid', $newuserid);
$newsession->set('loggedin', 1);
$newsession->set('bypass', 1);
$newsession->set_session_visibility(($vbulletin->superglobal_size['_COOKIE'] > 0));
$vbulletin->session =& $newsession;

I have set it in global_start. It logs the user fine! but the problem is the first time it logs the user in, it does not show the user as logged in on navbar. However, when I refresh the page, shows the user as logged in.

I believe, I am defining the session after the page is loaded.

Question 1:
How can I escape the login redirect and log the user directly in without refreshing?

It would be of big help if someone could answer my questions ASAP.

Cheers,
Kaiser.

[LunchBreak]

Could anyone please help me with this?
I believe it is cookie problem since I am not using the login redirect!