function export($fn, $fmt = SFC_FORMAT_RAW)
{
if ($fmt == SFC_FORMAT_TXT) {
$fp = fopen($fn, 'w');
foreach ($this->desktop->cards as $card) {
fputs($fp, $card->question . ' : ' . $card->answer . "\n");
}
fclose($fp);
} else {
$desktop = new Desktop();
foreach ($this->desktop->cards as $card) {
$desktop->add(new Card($card->question, $card->answer, $card->examples), true);
}
$desktop->save($fn);
}
}
