diff --git a/buttonarea.py b/buttonarea.py
index 6708714..33f27f6 100644
--- a/buttonarea.py
+++ b/buttonarea.py
@@ -99,8 +99,8 @@ class ButtonArea(QWidget):
 
     def get_current_state(self):
         label_button = self.get_checked_label_button()
-        result = {}
         if label_button != None:
+            result = {}
             label = str(label_button.text())
             if self.label_properties.has_key(label):
                 if self.label_properties[label].has_key("type"):
@@ -112,7 +112,9 @@ class ButtonArea(QWidget):
                         checked_button = button_list.get_checked_button()
                         if checked_button != None:
                             result[button_list.name] = str(checked_button.text())
-        return result
+            return result
+
+        return None
 
     def clickedButton(self):
         button = self.sender()
@@ -140,7 +142,7 @@ class ButtonArea(QWidget):
     def load(self, config_filepath):
         execfile(config_filepath)
         self.init_button_lists()
-        
+
 def main():
     app = QApplication(sys.argv)
 
diff --git a/labeltool.py b/labeltool.py
index f5c574f..86944df 100755
--- a/labeltool.py
+++ b/labeltool.py
@@ -50,6 +50,7 @@ class MainWindow(QMainWindow):
         self.buttonarea = ButtonArea()
         self.buttonarea.load("example_config.py")
         self.ui.dockAnnotationButtons.setWidget(self.buttonarea)
+        self.connect(self.buttonarea, SIGNAL("stateChanged(state)"), self.scene.setMode)
 
         self.treeview = AnnotationTreeView()
         self.ui.dockInformation.setWidget(self.treeview)