code: function(o, s) {
      s = s.replace(/\[(\w+)\]/g, '.$1');
      s = s.replace(/^\./, '');
      var a = s.split('.');
      for (var i = 0, n = a.length; i < n; ++i) {
          var k = a[i];
          if (k in o) {
              o = o[k];
          } else {
              return;
          }
      }
      return o;
  }
docs: from http://stackoverflow.com/a/6491621/1715949