You have published a Google Apps Script as a public web app that returns data as JSON but when you try to make an AJAX call to this web app using jQuery, you get the “Cross Origin” error.
Your AJAX request is blocked by the browser because of the “same origin policy” that disallows reading the remote resource at script.google.com. An easy workaround to this problem is JSONP or JSON with a prefix. With JSONP, the client’s browser won’t enforce the same origin policy but for that to work, you would need to modify your Google Script web app to return results in JSONP format.
Here’s an example web app that return JSONP results.