Communicating with inernet from Console application

Following code can be used to communicate with internet from a console application.

using System;
using System.Security.Cryptography;
using System.Text;
using System.Net.Sockets;
using System.IO;

namespace GirderInternetEventClient
{

public class GirderInternetEventClient
{
public GirderInternetEventClient()
{

}

public static void Main(string[] args)
{

if (args.Length == 4)
{
sendEventString(args[0], int.Parse(args[1]), args[2], args[3]);
return;
}

Console.WriteLine("Girder Internet Event Client");

Console.Write("Enter host [localhost]: ");

string host = Console.ReadLine();

if (host.Equals("")) host = "localhost";

Console.Write("Enter port [1024]: ");

string port = Console.ReadLine();

if (port.Equals("")) port = "1024";

Console.Write("Enter password [NewDefPWD]: ");

string password = Console.ReadLine();

if (password.Equals("")) password = "NewDefPWD";

Console.Write("Enter event [CR ends]: ");

string event_string = Console.ReadLine();

while (!event_string.Equals(""))
{
sendEventString(host, int.Parse(port), password, event_string);

Console.Write("Enter event [CR ends]: ");

event_string = Console.ReadLine();
}

Console.WriteLine("Done");
}

public static String getHexString(byte[] bytes)
{
String hex_string = "";
byte[] item = { 0 };

for (int i = 0; i < bytes.Length; i++)
{
item[0] = bytes[i];
hex_string += BitConverter.ToString(item);
}

return hex_string;
}

public static String getMD5String(String str)
{
MD5 md5 = new MD5CryptoServiceProvider();

byte[] result = md5.ComputeHash((new UTF8Encoding()).GetBytes(str));

return getHexString(result);
}

public static void sendEventString(String hostname, int port, String password, String event_string)
{
TcpClient tcpClient = new TcpClient();

try
{
tcpClient.Connect(hostname, port);

NetworkStream networkStream = tcpClient.GetStream();
StreamReader input = new StreamReader(networkStream);
StreamWriter output = new StreamWriter(networkStream);
output.AutoFlush = true;

output.WriteLine("quintessence");
String cookie = input.ReadLine();
output.WriteLine(getMD5String(cookie + ":" + password));
String accept_result = input.ReadLine();

if (accept_result.Equals("accept"))
{
output.WriteLine(event_string);

output.WriteLine("close");
}

}
finally
{
tcpClient.Close();
}
}
}
}