Clean url with rewrite rule does not work

Clean url with rewrite rule does not work

I read some tutorials about getting clean urls. I tried some of the codes
they gave in the tutorials but I can't get a simple example to run...
I would like to change: http://domain.com/brigandze/mannen/index.php?p=0
To: http://domain.com/brigandze/mannen/0/
I used this code and put it in the directory domain.com/brigandze/mannen/
I have this code in my htaccesfile:
RewriteEngine on
RewriteRule ^([0-9]+)/?$ index.php?p=$1 [NC,L]