ajax assignment - not working - looking for help on Cross Origin Resource Sharing

In ajax.js you'll see thant I'm tinkering with a basic ajax request implementation, very similar to the examples on MDN. 

The response I get from http://rs.hankyates.com:3000/content is 'No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' is therefore not allowed access.' 

I've read up this here: https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS

The response error makes it look like its a problem with the service not setting a response header to allow for cross domain requests -- but I know that jQuery works, so there must be something I can do.