Content/News pages

Sorry if this seems a completely stupid question but.

http://rhenderson1987.co.uk/index.php

Thats my site, I have cutenews working fine, but any time I try and include an extention for the .html files so they appear where the news is i get errors, is their a join script I'm meant to be using so it either shows the news on the index page or the content on the other pages i.e members.html/donate.html

Thanks in advance