function sell_edit()
{
    $session = Session::getInstance();
    if (!$session->checkLogin()) {
        return false;
    }
    $sell = new Sell();
    $sell->id = isset($_POST['sell']) ? $_POST['sell'] : "";
    $sell->status = isset($_POST['status']) ? $_POST['status'] : "";
    $sell->update();
    if (isset($_POST['payment']) && is_numeric($_POST['payment'])) {
        $sellPayment = new SellPayment();
        $sellPayment->sellid = isset($_POST['sell']) ? $_POST['sell'] : "";
        $sellPayment->amount = isset($_POST['payment']) ? $_POST['payment'] : "";
        $sellPayment->add();
    }
}