TcpClient client;
        const int portNO = 60000;
        const int localport = 2290;

        private void button1_Click(object sender, EventArgs e)
        {
            if (client != null)
            {
                client.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.DontLinger, true);
                //client.Close();
                
                
                //socketListen.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);

            }
            //else
            //{
                IPAddress ipAddress = Dns.GetHostEntry(Dns.GetHostName()).AddressList[0];
                IPEndPoint ipLocalEndPoint = new IPEndPoint(ipAddress, localport);
                client = new TcpClient(ipLocalEndPoint);
                client.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
                client.Connect("127.0.0.1", portNO);
                string msg = "LOGEIN";
                byte[] buffer = System.Text.Encoding.Default.GetBytes(msg);
                int i = client.Client.Send(buffer);
                Console.ReadLine();
            //}
        }

        private void button2_Click(object sender, EventArgs e)
        {
            client.Client.Disconnect(true);
            //client.Dispose();
            client.Close();
        }