code: def on_select_high_level(self,event,called_by_parent=False):
          
          UPPER_LEVEL=self.level_box.GetValue()
  
          if UPPER_LEVEL=='sample':
              self.level_names.SetItems(self.parent.samples)
              self.level_names.SetStringSelection(self.parent.Data_hierarchy['sample_of_specimen'][self.parent.s])
  
          if UPPER_LEVEL=='site':
              self.level_names.SetItems(self.parent.sites)
              self.level_names.SetStringSelection(self.parent.Data_hierarchy['site_of_specimen'][self.parent.s])
  
          if UPPER_LEVEL=='location':
              self.level_names.SetItems(self.parent.locations)
              self.level_names.SetStringSelection(self.parent.Data_hierarchy['location_of_specimen'][self.parent.s])
  
          if UPPER_LEVEL=='study':
              self.level_names.SetItems(['this study'])
              self.level_names.SetStringSelection('this study')
  
          if not called_by_parent:
              self.parent.level_box.SetStringSelection(UPPER_LEVEL)
              self.parent.onSelect_high_level(event,True)
  
          self.on_select_level_name(event)
docs: alters the possible entries in level_names combobox to give the user selections for which specimen interpretations to display in the logger
          @param: event -> the wx.COMBOBOXEVENT that triggered this function