+# class RequireDateIfUserDefined(formencode.validators.FormValidator):
+# "requires that date_userdefined is not empty if date_invalid == 'userdefined'"
+# def _to_python(self, value_dict, state):
+# # if not value_dict.get('date_invalid'): ... # This is _not_ checked because this should be checked elsewhere
+# if value_dict.get('date_invalid') == 'userdefined' and not value_dict.get('date_userdefined'):
+# value = value_dict.get('date_userdefined')
+# raise formencode.Invalid('Es muss ein Wert eingegeben werden', value, state, error_dict={'date_userdefined': formencode.Invalid(self.message('empty', state), value, state)})
+# return value_dict
+#
+#
+# class ChangeDateInvalidForm(formencode.Schema):
+# allow_extra_fields = True
+# filter_extra_fields = True
+# date_invalid = formencode.validators.OneOf(['no_change', 'tomorrow', 'one_week', 'two_weeks', 'one_week_more', 'end_of_saison', 'now', 'userdefined'], not_empty=True)
+# date_userdefined = wrpylib.wrvalidators.DateTimeNoSec
+# chained_validators = [RequireDateIfUserDefined()]