I am writing a firefox extension that interacts with a JSON server interface. I receive a url to the server which then redirects to the client site that provides the cookie. I need to be able to set this cookie in the users browser without physically loading it in the browser. Is this possible through an AJAX call?

I tried using a hidden iframe, however firefox does not seem to like a php redirect in the iframe. My current solution is to load the site in a second tab that never gains focus and then auto close it when the cookie is set. This is very messy and would prefer something more streamlines.

Any thoughts?