Crated messagebox for no devices

src/AppFrame.h

@@ -51,12 +51,15 @@ public:
     void saveSession(std::string fileName);
     bool loadSession(std::string fileName);
 
+    void OnMessage(std::string message, std::string title);
+
 private:
     void OnMenu(wxCommandEvent& event);
     void OnClose(wxCommandEvent& event);
     void OnNewWindow(wxCommandEvent& event);
     void OnIdle(wxIdleEvent& event);
 
+
     ScopeCanvas *scopeCanvas;
     SpectrumCanvas *spectrumCanvas;
     WaterfallCanvas *waterfallCanvas;