I own this website : http://www.[my site].com/ and I have a forum for it : http://www.[my site].com/vb
I want to mix both so ... if somebody logged in from the website he will login in the forum.
my problem is that the forum user login ... uses an md5 password encoding but it is different than the md5 password incoding in my website ... how I can make both of them use the same encoding ? btw ... the forum template is too complicated.
note : I did combine both templates on one database.
One approach is use the "Proxy Connect" approach pioneered by Vanilla forums:
http://vanillaforums.org/docs/singlesignon
Another approach, since I assume the VB in your forum's link stands for vBulletin, is to look for an SSO (sing sign on) plug in or a developer to assist with this process.
You say that you "combined both templates on one database". I'm not sure what this means but you should be able to delve into the code and encrypt passwords in the same way....or combine/mirror the password for each user's forum password with the password on the main site. The proxy connect approach outlined above is probably better.
Finally, you could do nothing at this time and wait to see if your forum catches on. If you are able to get traction then perhaps it warrants an investment in time/money to streamline the sign on. However, in my experience, users have no qualms about creating a separate account to join a forum provided with fresh and compelling content. I'd focus your energy on seeding the forum and making it interesting/active/lively.
Good luck!