// List of allowed domains.

(array) $referers = array('newmedia24.de','tuxnet24.de');

// Go away if your referer is not in the domain list.

if ( !referer($_SERVER['HTTP_REFERER']) )

	header("Location: https://www.cia.gov/");

// *****************************************************************

// This function check if the $ENV{'HTTP_REFERER'} can access this page.

function referer ( $referer ) {

global $referers;

if ( !empty( $referer ) ) {

	foreach ( $referers as $host ) {

		if ( preg_match( "/https?:\/\/([^\/]*)$host/i", $referer ) ) { return True; break; }

	}

} else return True;

return False;

}