site url is without www

Hello,

In a mail notification, when I use replacement patterns @requestee_pending_link or @requester_link or @site_url (anything that prints link) It prints the url of the site without www. I mean instead of http://www.mysite.com/blabla it only prints http://mysite.com/blabla

I know both url styles work but if a user is logged in to the address with www, he needs to log in to the site without www again. A little bit annoying.

Is there a way to fix thins??

Thanks in advance...

Sinan