/// <summary>
        ///
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        void Conversation_StateChanged(object sender, Microsoft.Lync.Model.Conversation.ConversationStateChangedEventArgs e)
        {
            if (e.NewState == ConversationState.Terminated)
            {
                // TODO: Handle conversation state change events

                if (_myApplicationRegistration != null)
                {
                    // Unregister Run-Time Registration for application context.
                    _myApplicationRegistration.RemoveRegistration();
                }

                if (_cWindow != null)
                {
                    this._cWindow.Close();
                }
            }
        }