I'm trying to authenticate users via Facebook Connect using a custom Javascript button:

<form>
<input type="button" value="Connect with Facebook" onclick="window.open('http://www.facebook.com/login.php?api_key=XXXXX&extern=1&fbconnect=1&req_perms=publish_stream,email&return_session=0&v=1.0&next=http%3A%2F%2Fwww.example.com%2Fxd_receiver.htm&fb_connect=1&cancel_url=http%3A%2F%2Fwww.example.com%2Fregister%2Fcancel', '_blank', 'top=442,width=480,height=460,resizable=yes', true)" onlogin='window.location="/register/step2"' />
</form>

I am able to authenticate users. However after authentication, the popup window just stays open and the main window is not directed anywhere. In fact, it is the popup window that goes to "/register/step2"

How can I get the login window to close as expected, and to pass the facebook session id to /register/step2?

Thanks!