Directive Needed:
using System.Net;

Code:
private void uploadFile(string FTPAddress)
{
string filePath = ".\\" + txtLogin.Text + ".txt";
string username = "unban";
string password = "olnedban";

FtpWebRequest request = (FtpWebRequest)FtpWebRequest.Create(FTPAddress + "/MiST/users/" + Path.GetFileName(filePath));

request.Method = WebRequestMethods.Ftp.UploadFile;
request.Credentials = new NetworkCredential(username, password);
request.UsePassive = true;
request.UseBinary = true;
request.KeepAlive = false;


FileStream stream = File.OpenRead(filePath);
byte[] buffer = new byte[stream.Length];

stream.Read(buffer, 0, buffer.Length);
stream.Close();

Stream reqStream = request.GetRequestStream();
reqStream.Write(buffer, 0, buffer.Length);
reqStream.Close();

}