USERCP Refferal Link?

[vitrag24]

I got code but it's not filling refferal userid in registration field yet..

<!-- ############## REFERRAL LINK ############## -->
<div class="block" id="referral_link">
<h2 class="blockhead">Referral Link</h2>
<ol class="blockbody settings_form_border" id="referral_link">
<li>Your referral link is <a href="{vb:raw vboptions.bburl}/register.php?referrerid={vb:var bbuserinfo.userid}">{vb:raw vboptions.bburl}/register.php?referrerid={vb:var bbuserinfo.userid}</a></li>
</ol>
</div>
<!-- ############## REFERRAL LINK ############## -->

BTW, it's showing link like http://www.domain.com/register.php?referrerid=X but on clicking that link, in refferal field, it's blank instead it shd be filled automatically..

i'm on vb 4.