-extern void error_dialog (wxWindow *, std::string);
-extern wxStaticText* add_label_to_sizer (wxSizer *, wxWindow *, std::string, int prop = 0);
+extern void error_dialog (wxWindow *, wxString);
+extern wxStaticText* add_label_to_sizer (wxSizer *, wxWindow *, wxString, int prop = 0);
+extern wxStaticText* add_label_to_grid_bag_sizer (wxGridBagSizer *, wxWindow *, wxString, wxGBPosition, wxGBSpan span = wxDefaultSpan);