while (true)
            {
                IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, 0);
                Byte[] receivedBytes = udpClient.Receive(ref RemoteIpEndPoint);
                string returnData = Encoding.ASCII.GetString(receivedBytes);
                MessageBox.Show("wiadomosc");
                lbConnections.Items.Add(RemoteIpEndPoint.Address.ToString() + ":" + returnData);
                this.Refresh();

            }