docs: function (elem, elemName, func)
      {
          var i, childNode;
  
          for (i = 0; i < elem.childNodes.length; i++) {
              childNode = elem.childNodes[i];
              if (childNode.nodeType == Strophe.ElementType.NORMAL &&
                  (!elemName || this.isTagEqual(childNode, elemName))) {
                  func(childNode);
              }
          }
      }