private void _sendButton_Click(object sender, EventArgs e)
        {
            if (String.IsNullOrWhiteSpace(_textBox.Text))
                return;
            else
            {

                String message = _textBox.Text;

                AddNewMessage(Settings.GetInstance().CurrentUser.Fullname, message);

                string destination;
                if (isSpecialist)
                    destination = client.Username;
                else
                    destination = "";

                JObject json = new ChatPacket(message, destination, Settings.GetInstance().authToken, broadcastCheckbox.Checked).ToJsonObject();
                TCPController.Send(json.ToString());
                _textBox.Text = "";
            }
        }