Actions for includes in php

[proxyMX]

hi there,
i was wondering if there was any way i could simply use one page for includes, instead of having to save the normal way.

Normally youd alter the includes code to the specific page eg
index.php's includes would be indexinc.php,navigation.php,extras.php

news includes would be
newsinc.php, navigation.php,extras.php

Basically what i want to do is for every inc page of my site create an action from the main template that would display the unique included page to each

eg
index.php?action=news
would include newsinc.php and the navigation and extras files
index.php?action=freebies
would include freeinc.php and the navigation and extras files

anyway i can do this? im a total newbie to php