+#define wxDEFAULT_FRAME_STYLE (wxSYSTEM_MENU|wxRESIZE_BORDER | wxMINIMIZE_BOX | wxMAXIMIZE_BOX | wxTHICK_FRAME | wxSYSTEM_MENU | wxCAPTION | wxCLIP_CHILDREN)
+
+#ifdef __WXMSW__
+# define wxDEFAULT_DIALOG_STYLE (wxSYSTEM_MENU|wxCAPTION|wxTHICK_FRAME)
+#else
+// Under Unix, the dialogs don't have a system menu. Specifying
+// wxSYSTEM_MENU here, will make a close button appear.
+# define wxDEFAULT_DIALOG_STYLE (wxCAPTION)
+#endif
+