/// <summary>
        /// συνάρτηση διαχείρισης των επιλογών που έγιναν στο TrayIcon
        /// </summary>
        private void Button_OnPushed(object sender)
        {
            String msg = sender as string;
            if (msg.Equals("SETTINGS"))
            {
                loadPreferences();
                this.Visibility = Visibility.Visible;
            }
            else if (msg.Equals("TRANSLATOR"))
            {
                translatorUI = new TranslatorUI();
                translatorUI.OnClose += translatorUI_OnClose;
                translatorUI.Show();
                this.Visibility = Visibility.Collapsed;
            }
            else if (msg.Equals("START/STOP"))
            {
                startStopTranslate();

            }
            else if (msg.Equals("EXIT"))
                Application.Current.Shutdown();
        }
        /// <summary>
        /// συνάρτηση που χρησιμοποιείται για την μετάφραση του επιλεγμένου κειμένου
        /// </summary>
        private void translate()
        {
            string source = hotKeyToTranslate.GetTextFromFocusedControl(new WindowInteropHelper(this).Handle);
            string result = Translate.translate(source);
            if (result.Equals("TranslatorException"))
            {
                Translate.init();
                result = Translate.translate(source);
            }
            Console.WriteLine("TRANSLATE source :" + source + " , result : " + result);

            notifyTray.ShowBalloonTip("Translator", "Trying to translate message...");

            if (translatorUI == null)
            {
                translatorUI = new TranslatorUI();
                translatorUI.OnClose += translatorUI_OnClose;
                translatorUI.setSourceText(source);
                translatorUI.setResultText(result);
                translatorUI.Show();
            }
            else
            {
                translatorUI.setSourceText(source);
                translatorUI.setResultText(result);
                if (translatorUI.WindowState == WindowState.Minimized)
                    translatorUI.WindowState = WindowState.Normal;
                translatorUI.Focus();
            }
        }