auto login to pop-up window in external website

Is it possible to use javascript to automatically login to an external secure website that has a pop-up box for the login? It is not a form so I can not see the post or password parameters.

Thanks.

All a form does is post data to a server-side authentication system. AJAX can do the same thing. It's still posting data just as a form does. Just figure out where it's going and you can post to it.

However, note that if the author does it right, he/she will program the server to only accept requests from the same domain. In that case, you're out of luck.