New URL...HELP

[Stylee]

I am trying to point a new URL to my forum. Which file do I edit to reflect the new url?

Example, I have 2 url's pointing to my site, and they will both get me to my forum, but when I type .www.newwurl.com/forum it takes me to the forum, but in the address bar, it goes back to www.oldurl.com/forum

Now if I type www.newurl.com/forum/index.php in the address bar, it will take me there and will keep www.newurl.com in the address bar the whole time.

I looked in the index.php file in the main folder, and cannot find reference to www.oldurl anywhere.

can someone help?

[Stylee]

Oh yeah, and I did change it to newurl.com in the php admin under config. and that didnt work

[A_Jelly_Doughnut]

What about the cookie settings? Did you change them?

[Stylee]

Cookie domain nothing there
Cookie name phpbb2mysql
Cookie path /
and cookie secure is disabled.

That was the only thing that was ever there.
Should I change that or edit a file?

Also, this is on a My-SQL database on a web server.