Access to restricted URI denied" code: "1012

I was working on the interface for our catalogue/directory structure. We use great JavaScript library jQuery and I came up to this problem:

Access to restricted URI denied" code: "1012
xhr.open(type, s.url, s.async);

(This error is produced in Firebug, plug-in for Firefox.)

The error occurs when it tries to do an AJAX request call to local resource. So to solve this problem you need to deploy your files to your web server or run one locally.