bogu: I don't think the Install forum applies here since this has nothing to do with installing PHP. Granted, there isn't really any suitable place for this type of question (or the .htaccess/mod_rewrite questions we get here), so I'd say any general section such as Newbies or General Help is fine.
rahaiffi: What do you mean by "its failed" ? What happened when you restarted your webserver (you did restart the webserver, right?) and attempted to view the directory? Did you get an error message? Did you check your Apache error logs?
Your syntax looks fine as per the Apache manual.