This file is a trivial file but necessary nonetheless to give the project a home page. All it does is display a simple welcome message. In a finished application, this would be where you sell the virtues of your site to encourage signups.
Incidentally, seeing as all the MySQL tables have been created and the include files saved, you can now load Example 20-4, index.php, into your browser to get your first peek at the new application. It should look like Figure 20-1.
<?php // index.php include_once 'rnheader.php'; echo "<h3>Home page</h3> Welcome, please Sign up and/or Log in to join in."; ?>