-        dlg = wxMessageDialog(frame, 'This demo requires the XML package.  '
-                              'See http://www.python.org/sigs/xml-sig/',
-                          'Sorry', wxOK | wxICON_INFORMATION)
+        dlg = wx.MessageDialog(
+                frame, 'This demo requires the XML package.  '
+                'See http://www.python.org/sigs/xml-sig/',
+                'Sorry', wx.OK | wx.ICON_INFORMATION
+                )
+