Sorry I have forget information !!

When I want to restart Nginx I have error :

[code]
Bender:~# /etc/init.d/nginx restart
Restarting nginx: 2009/07/30 18:35:44 [emerg] 2646#0: "if" directive is not allowed here in /etc/nginx/sites-enabled/default:24
nginx.
[/code]
[The error is in [u]if ( $host ~* "(.*)\.([a-zA-Z0-9_-]*\.[a-zA-Z]{2,4})" )[/u] ]