Setup Paypal pro in asp.net c#

I used the following function for Paypal pro.

public static string DoDirectPaymentCode(string paymentAction, string amount, string creditCardType, string creditCardNumber, string expdate_month, string cvv2Number, string firstName, string lastName, string address1, string city, string state, string zip, string countryCode, string currencyCode)
{
NVPCallerServices caller = new NVPCallerServices();
IAPIProfile profile = ProfileFactory.createSignatureAPIProfile();
/*
WARNING: Do not embed plaintext credentials in your application code.
Doing so is insecure and against best practices.
Your API credentials must be handled securely. Please consider
encrypting them for use in any production environment, and ensure
that only authorized individuals may view or modify them.
*/

// Set up your API credentials, PayPal end point, API operation and version.
profile.APIUsername = "sdk-three_api1.sdk.com";
profile.APIPassword = "QFZCWN5HZM8VBG7Q";
profile.APISignature = "AVGidzoSQiGWu.lGj3z15HLczXaaAcK6imHawrjefqgclVwBe8imgCHZ";
profile.Environment = "Live";
caller.APIProfile = profile;

NVPCodec encoder = new NVPCodec();
encoder["VERSION"] = "51.0";
encoder["METHOD"] = "DoDirectPayment";

// Add request-specific fields to the request.
encoder["PAYMENTACTION"] = paymentAction;
encoder["AMT"] = amount;
encoder["CREDITCARDTYPE"] = creditCardType;
encoder["ACCT"] = creditCardNumber;
encoder["EXPDATE"] = expdate_month;
encoder["CVV2"] = cvv2Number;
encoder["FIRSTNAME"] = firstName;
encoder["LASTNAME"] = lastName;
encoder["STREET"] = address1;
encoder["CITY"] = city;
encoder["STATE"] = state;
encoder["ZIP"] = zip;
encoder["COUNTRYCODE"] = countryCode;
encoder["CURRENCYCODE"] = currencyCode;

// Execute the API operation and obtain the response.
string pStrrequestforNvp = encoder.Encode();
string pStresponsenvp = caller.Call(pStrrequestforNvp);

NVPCodec decoder = new NVPCodec();
decoder.Decode(pStresponsenvp);
return decoder["ACK"];

}


The following references are required:
using com.paypal.sdk.services;
using com.paypal.sdk.profiles;
using com.paypal.sdk.util;

The follwing dlls are required:
paypal_base.dll and log4net.dll