rearrange the links at top

wow. thanks confusing o.o
i opened the file and found where its at but i have no idea how to do it

Hello, I use this topic for I'm trying for hours to add navlinks in the navlinks menu and it always tells me :

Notice: Undefined index: newsletter in /home/www/c23ee494339f4673173c93ff37a3a87a/web/forum-scpo/include/functions.php on line 437

I'm trying to put my newsletter page in the navlinks.

I try with this syntaxe on line 437 in the functions.php file:

$links['newsletter'] = '<li id="navnewsletter"'.((FORUM_PAGE == 'newsletter2') ? ' class="isactive"' : '').'><a href="'.forum_link($forum_url['newsletter']).'">'.$lang_common['Newsletter'].'</a></li>';

I put the file newsletter2.htm in the forum folder in my FTP server. Is it useful or this file can be placed anywhere ?
I also add a line "newsletter" in the forum_urls.php file, and in the lang/common.php file.
Should I write the complete url on the forum_urls.php file ?

Can you tell me what is wrong in this syntaxe ? and how can I add navlinks with pages that are not in the classic forum folder (i.e. htm pages that I've made myself and that are not in the forum), as you have on this website (for instance wiki, timeline...).

I really don't understand how to add new navlinks ! It's awful, I'm on it for hours and can't understand why it doesn't work...

Sorry if this issue has ever been raised elsewhere, and great thanks for eventual answers...

Kind regards,