if (!empty($_GET['src']) && empty($phpThumb->config_allow_local_http_src)
    && preg_match('#^http://' . @$_SERVER['HTTP_HOST'] . '(.+)#i', $_GET['src'], $matches)) {
    $phpThumb->ErrorImage('It is MUCH better to specify the "src" parameter as "' . $matches[1] . '" instead of "' . $matches[0] . '".' . "\n\n" . 'If you really must do it this way, enable "allow_local_http_src" in phpThumb.config.php');
}