public function payment() {

        if($this->request->post['pay_balance']) {

            $server = "http://www.free-kassa.ru/merchant/cash.php";
            $id = "35915";
            $password1 = "0hi1kyb9";

            if($newPaymentID = Builder::table("payments")->create(['user_id' => $this->session->data['user_id'], 'payment_sum' => $this->request->post['sum'], 'payment_time' => 'NOW()'])){
                $signature = md5("$id:".$this->request->post['sum'].":$password1:$newPaymentID");
                $url = $server;
                /* Параметры: */
                $url .= "?m=$id";
                $url .= "&oa=".$this->request->post['sum'];
                $url .= "&o=$newPaymentID";
                $url .= "&s=$signature";
                $url .= "&i=125";

                redirect($url);
            }
        }

        return view("payment", $data);
    }

    public function handler() {

        model("User");

        if($this->request->server['REQUEST_METHOD'] == 'GET') {
            $ammount = $this->request->get['AMOUNT'];
            $invid = $this->request->get['MERCHANT_ORDER_ID'];
            $signature = $this->request->get['SIGN'];

            $password2 = "16c7hkt9";

            if(!Builder::table("payments")->where('payment_id', $invid)->first()) {
                $errorPOST = "Invalid invoice!";
            }
            elseif(strtoupper($signature) != strtoupper(md5("35915:$ammount:$password2:$invid"))) {
                $errorPOST = "Invalid signature!";
            }

            if(!$errorPOST) {

                $payment = Builder::table("payments")->where("payment_id", $invid)->first();
                Builder::table("payments")->where("payment_id", $invid)->set(['payment_status' => 1])->update();

                $this->UserModel->plusBalance($payment['payment_sum'], $payment['user_id']);

                exit("YES");
            } else {
                exit("Error: $errorPOST");
            }
        } else {
            exit("Error: Invalid request!");
        }
    }