diff --git a/Window.py b/Window.py
index f32f47a..bfd55f3 100644
--- a/Window.py
+++ b/Window.py
@@ -411,7 +411,11 @@ class Window:
         if self.mark is None:
             self.mark = datetime.now()
             self.update_status_event()
+        else:
+            # TODO: error message?
+            pass
 
     def out_event(self, widget, data=None):
         self.mark = None
         self.update_status_event()
+        # TODO: bundle elapsed time or discard?