It uses IFRAME lol here's code from xtina.pl
layout...
<IFRAME SRC=<? echo $_GET['page'] . ".php"; ?> WIDTH=489 HEIGHT=420 FRAMEBORDER=0 SCROLLING=AUTO MARGINWIDTH=5 MARGINHEIGHT=5 ;></IFRAME>
layout...
and you can use
layout...
<IFRAME SRC=<? echo "nav_pages/" . $_GET['page'] . ".php"; ?> WIDTH=489 HEIGHT=420 FRAMEBORDER=0 SCROLLING=AUTO MARGINWIDTH=5 MARGINHEIGHT=5 ;></IFRAME>
layout...
so now index.php?page=articles show page nav_pages/articles.php 🙂
or better (maybe for you)
layout...
<? include "nav_pages/" . $_GET['page'] . ".php"; ?>
layout...
and it include nav_pages/variable_page.php script 🙂