// Liste mit gueltigen Domains...

$referers=array('www.phpXpress.de', 'www.m-newdesign.de', 'meine-awo.de');

// checken of Referer gueltig ist...

if ( referer($_SERVER['HTTP_REFERER']) ) echo "good"; else echo "bad";

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

// Referer checken...

function referer($referer) {

global $referers;

if (!empty($referer)) {

	foreach ($referers as $host) {

		if ( preg_match("/https?:\/\/([^\/]*)$host/i", $referer) ) { return 1; break; }

	}

} else return 1;

return 0;

}