Can we make Ajax request to a different instance of server(different port) running on the same machine
See Question&Answers more detail:osCan we make Ajax request to a different instance of server(different port) running on the same machine
See Question&Answers more detail:osDifferent port means different domain for the browser. So you will hit the cross-domain barrier.
Like Stuart said, you could try using JSONP.
If you are using jQuery, I'd recommend http://code.google.com/p/jquery-jsonp/ if you want it to be as painless as possible.