docs: function (event) {
        switch (attribute.type) {
          case 'Date':
            attribute.value = (input.value === '') ? null : attribute.coerce(input.value);
            if (attribute.value != null) {
              var mm = attribute.value.getMonth() + 1;
              var dd = attribute.value.getDate();
              var yyyy = attribute.value.getFullYear();
              if (mm < 10) mm = '0' + mm;
              if (dd < 10) dd = '0' + dd;
              input.value = mm + '/' + dd + '/' + yyyy;
            } else {
              input.value = '';
            }
            break;
          default:
            attribute.value = (input.value === '') ? null : attribute.coerce(input.value);
            if (attribute.value != null)
              input.value = attribute.value;
            break;
        }
        attribute.validate(function () {
        });
      }