code: function(value, range) {
        var
          intRegExp = $.fn.form.settings.regExp.integer,
          min,
          max,
          parts
        ;
        if( !range || ['', '..'].indexOf(range) !== -1) {
          // do nothing
        }
        else if(range.indexOf('..') == -1) {
          if(intRegExp.test(range)) {
            min = max = range - 0;
          }
        }
        else {
          parts = range.split('..', 2);
          if(intRegExp.test(parts[0])) {
            min = parts[0] - 0;
          }
          if(intRegExp.test(parts[1])) {
            max = parts[1] - 0;
          }
        }
        return (
          intRegExp.test(value) &&
          (min === undefined || value >= min) &&
          (max === undefined || value <= max)
        );
      }
docs: is valid integer or matches range