private void doPay() {

        int rand = new Random().nextInt();

        /*Mandatory Field*/
        MandatoryFieldModel mandatoryFieldModel = new MandatoryFieldModel("", "", "200",
                "trans_" + rand, CurrencyType.BDT, SdkType.TESTBOX, SdkCategory.BANK_LIST);

        /*Call for the payment*/
        PayUsingSSLCommerz.getInstance().setData(this, mandatoryFieldModel, new OnPaymentResultListener() {
            @Override
            public void transactionSuccess(TransactionInfo transactionInfo) {

                // If payment is success and risk label is 0.
                if (transactionInfo.getRiskLevel().equals("0")) {
                    Log.d(TAG, "Transaction Successfully completed");
                    Log.d(TAG, transactionInfo.getTranId());
                    Log.d(TAG, transactionInfo.getBankTranId());
                    Log.d(TAG, transactionInfo.getAmount());
                    Log.d(TAG, transactionInfo.getStoreAmount());
                    Log.d(TAG, transactionInfo.getTranDate());
                    Log.d(TAG, transactionInfo.getStatus());
                }
                // Payment is success but payment is not complete yet. Card on hold now.
                else {
                    Log.d(TAG, "Transaction in risk. Risk Title : " + transactionInfo.getRiskTitle().toString());
                }

            }

            @Override
            public void transactionFail(TransactionInfo transactionInfo) {
                // Transaction failed
                Log.e(TAG, "Transaction Fail");
            }

            @Override
            public void error(int errorCode) {
                switch (errorCode) {
                    // Your provides information is not valid.
                    case ErrorKeys.USER_INPUT_ERROR:
                        Log.e(TAG, "User Input Error");
                        break;
                    // Internet is not connected.
                    case ErrorKeys.INTERNET_CONNECTION_ERROR:
                        Log.e(TAG, "Internet Connection Error");
                        break;
                    // Server is not giving valid data.
                    case ErrorKeys.DATA_PARSING_ERROR:
                        Log.e(TAG, "Data Parsing Error");
                        break;
                    // User press back button or canceled the transaction.
                    case ErrorKeys.CANCEL_TRANSACTION_ERROR:
                        Log.e(TAG, "User Cancel The Transaction");
                        break;
                    // Server is not responding.
                    case ErrorKeys.SERVER_ERROR:
                        Log.e(TAG, "Server Error");
                        break;
                    // For some reason network is not responding
                    case ErrorKeys.NETWORK_ERROR:
                        Log.e(TAG, "Network Error");
                        break;
                }
            }
        });
    }