Rewrite top level url to index.php

index.php

<?php
//header begin
/*
* Force url rewrite (www.website.com -> www.website.com/index.php)
*/
$req = $_SERVER['REQUEST_URI'];
if (strpos($req,"index.php") !== false) {//if true (good, no rewrite needed)
}else{ //redirect if false
	header('Location: index.php');
}
//end header
?>

This will basically force the browser to update index.php instead of using it's cache to load the top level website.