docs: function findByAttribute (start, attribute, maxDepth, stopper) {
          var target = start, expandoValue;
  
          while (maxDepth && target && target != stopper) {
              if (target.attributes) {
                  var expandoValue = target.attributes[attribute];
                  if (expandoValue) {
                      return expandoValue.nodeValue;
                  }
              }
              target = target.parentNode;
              maxDepth--;
          }
      }