$dfrn_id = ((x($_POST,'dfrn_id')) ? $_POST['dfrn_id'] : '');
$challenge = ((x($_POST,'challenge')) ? $_POST['challenge'] : '');
$dfrn_id = ((x($_POST,'dfrn_id')) ? $_POST['dfrn_id'] : '');
$challenge = ((x($_POST,'challenge')) ? $_POST['challenge'] : '');