Hello.

I've updated the OPML JavaScript Object Model to support OPML Attributes for Outlines, increasing flexibility for developers. I've also incorporated an instanceOf method (source unknown - please let me know if you recognize it!) to add type checking when inserting OPMLOutlineAttributes into the attribute array. The added instanceOf function is as follows:

function instanceOf(object, constructor)  while (object != null) {       if (object == constructor.prototype)          return true;       object = object.__proto__;    }    return false; }