'If you are using freewebs then you have to make a forum on a free forumhoster site.
Freebb.com
eAmped (phpBB)
(
Google Search)
And then add a link on your website going to that forum
<a href="yourforumlinkhere">Forum</a>
<a href="yourforumlinkhere" target="_blank">Forum</a> - To open the forum in a new window
Or you can change hoster to something like
Freehostia.com and host your website there with the forum in the same domain.