this is a little tricker, there are two steps involved:
1- Make CMSMS output the links without the .shtml extension.
2- Configure the server to forward the new formart to the correct page.
The first part is easy: open the config.php file and change:
$config['page_extension'] = '.shtml';
to
$config['page_extension'] = '';
The first part is over, now the second part:
1- On the root directory you will find a file named .htaccess (if you don't find it, you are suppose to upload it from the doc directory of the source package of CMSMS, or you can create an empty text file named .htaccess).
2- Download that file and open it, it should be like this:
php_flag magic_quotes_gpc Off
php_flag register_globals Off
php_flag session.use_trans_sid Off
# Make sure you have Options FollowSymLinks
# and Allow on
RewriteEngine On
#Rewrites page.shtml as index.php?page
RewriteRule ^(.+)\.shtml$ index.php?page=$1 [QSA]
Change the following line:
RewriteRule ^(.+)\.shtml$ index.php?page=$1 [QSA]
to
RewriteRule ^(.+) index.php?page=$1 [QSA]
And you are all set, upload and enjoy search engine friendly urls
