code: def start_element(self, tag, attrs):
          
          if tag == u'form':
              if u'action' in attrs:
                  url = attrs['action']
                  self.form = Form(url)
          elif tag == u'input':
              if self.form:
                  if 'name' in attrs:
                      key = attrs['name']
                      value = attrs.get('value')
                      self.form.add_value(key, value)
                  else:
                      log.warning(LOG_CHECK, "nameless form input %s" % attrs)
                      pass
              else:
                  log.warning(LOG_CHECK, "formless input´%s" % attrs)
                  pass
docs: Does nothing, override in a subclass.