Cannot Read default controller

Hi,
i'm having error loading my default controller. 
tried those .htaccess file but no luck.

folder structure:
htdocs
>codeigniter

www.mywebsite.com/codeigniter
it gives me 404 error
but when i put
www.mywebsite.com/codeigniter/welcome
it works.

my .htaccess

Code:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1 [L] 
</IfModule>

config.php

Code:

$config['base_url'] = 'http://www.mywebsite.com/codeigniter/';
$config['index_page'] = '';

Hey,

Did you put the .htaccess in the codeigniter folder?
And maybe you have to change the line with 'index.php/$1' into

Code:

 RewriteRule ^(.*)$ /codeigniter/index.php?/$1 [L]

Hope this helps!

-Roger