<?php $origin = $_GET["origin"] ? $_GET["origin"] : ""; header("timing-allow-origin: $origin"); ?> <!DOCTYPE HTML> <html> <head> <meta content="text/html; charset=utf-8" http-equiv="Content-Type" /> <title>Green Test Page</title> </head> <body style="background-color:#00FF00;"> <h1>Placeholder</h1> </body> </html>