Prevent Direct Access To PHP File
<p>Let's say I have two domains: <em>domainA.com</em> and <em>domainB.com</em>. On <em>domainB.com</em> im going to use an iframe to access a PHP file on <em>domainA.com</em>. </p>

<p>Is there a way I can set an <code>if/else</code> statement so that no user can access that PHP file by going to <code>domainA.com/file.php</code>? That file should only load from an iframe on <em>domainB.com</em>. </p>
