def auto_geocode_address
      address=self.send(auto_geocode_field).to_s
      geo=Geokit::Geocoders::MultiGeocoder.geocode(address)

      if geo.success
        self.send("#{lat_column_name}=", geo.send(:"#{lat_column_name}"))
        self.send("#{lng_column_name}=", geo.send(:"#{lng_column_name}"))
      else
        errors.add(auto_geocode_field, auto_geocode_error_message)
      end

      geo.success
    end
def auto_geocode_address
      address=self.send(auto_geocode_field).to_s
      geo=Geokit::Geocoders::MultiGeocoder.geocode(address)

      if geo.success
        self.send("#{lat_column_name}=", geo.send(:"#{lat_column_name}"))
        self.send("#{lng_column_name}=", geo.send(:"#{lng_column_name}"))
      else
        errors.add(auto_geocode_field, auto_geocode_error_message)
      end

      geo.success
    end
ClassMethods
 this is the callback for auto_geocoding