def add_itemref_properties(element)
      itemref = element.attribute('itemref')
      if itemref
        itemref.value.split(' ').each {|id| parse_elements(find_with_id(id))}
      end
    end
def add_itemref_properties(element)
      itemref = element.attribute('itemref')
      if itemref
        itemref.value.split(' ').each {|id| parse_elements(find_with_id(id))}
      end
    end
Add any properties referred to by 'itemref'