How to clean the working dir from .svn folders ?

[Damien Mistic]

Hi all,
so my problem is clear : I've a working dir and I want to clean it up from 
all .svn folders, how to ?
Knowing that I'm working un CLI within exec() function of PHP. Unfortunately 
I can't delete manually files and folders :

Warning: unlink(svn/.svn/all-wcprops) [function.unlink]: Permission denied 
in C:\wamp\www\lang_editor\include\functions.inc.php on line 325

And the 'export' function is not what I want because my aim is to delete the 
folder, not really get a clean copy.

If there is no way I think we must add a new function to SVN, such as 'svn 
unlink' or 'svn dissociate'

Regards, Damien.