Hi guys, i have a problem with my forum, i have this .htaccess:

# Comment the following line (add '#' at the beginning)
# to disable mod_rewrite functions.
# Please note: you still need to disable the hack in
# the vBSEO control panel to stop url rewrites.
RewriteEngine On

# Some servers require the Rewritebase directive to be
# enabled (remove '#' at the beginning to activate)
# Please note: when enabled, you must include the path
# to your root vB folder (i.e. RewriteBase /forums)
#RewriteBase /

#RewriteCond %{HTTP_HOST} !^www\.yourdomain\.com
#RewriteRule (.*) http://www.yourdomain.com/forums/$1 [L,R=301]

RewriteRule ^((urllist|sitemap_).*\.(xml|txt)(\.gz)?)$ vbseo_sitemap/vbseo_getsitemap.php?sitemap=$1 [L]

RewriteCond %{QUERY_STRING} !vbseourl=
RewriteCond %{REQUEST_URI} !(admincp/|modcp/|chat|cron)
RewriteRule ^(.*\.php)$ vbseo.php?vbseourl=$1 [L,QSA]

RewriteCond %{REQUEST_FILENAME} !\.(jpg|gif)$
RewriteRule ^(archive/.*)$ vbseo.php?vbseourl=$1 [L,QSA]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !^(admincp|modcp|clientscript|cpstyles|images)/
RewriteRule ^(.+)$ vbseo.php?vbseourl=$1 [L,QSA]

Then the url of my forum are http://www.domain.com/forum/forumdisplay.php?f=3 and i need to change forumdisplay.php?f=3