+ wxASSERT_MSG( (m_widget != NULL), "invalid frame" );
+ wxASSERT_MSG( (m_wxwindow != NULL), "invalid frame" );
+ wxASSERT_MSG( (m_mainWindow != NULL), "invalid frame" );
+ wxASSERT_MSG( (child != NULL), "invalid child" );
+ wxASSERT_MSG( (child->m_widget != NULL), "invalid child" );
+