<?php if ($page = "software") { include "software.php"; } elseif ($page = "moose") { include "moose.php"; } elseif ($page = "about") { include "about.php"; } else { include "default.php"; } ?>
The above code can be made simply by effectively using the Switch statement:
<?php switch ($page) { case "software": case "moose": case "about": include "$page.php"; break; default: include "default.php"; break; } ?>
Now, if REGISTER_GLOBALS is set off in php.ini, just replace $page with $_GET["page"], and it should work.