I've written some HTML/Javascript that sits on a third-party server for security reasons. This page performs a javascript post to another page on the same site. However, instead of responding with useful data, it instead wants to perform a redirect (if you would post via a normal HTML form to this page, it would redirect your browser). How can I process this process? I basically want to be able to extract the url's query parameters that it is trying to redirect with (and then put this link into a hidden form field).

Here is my basic ajax post...

$.ajax({
    url: '/someurl/idontcontrol', 
    data: serialized_form_data,
    async: false,
    type: 'POST',
    success: function(data, textStatus) {
        $('#redirect_link').val(WHAT_DO_I_PUT_HERE);
    }
});

Note that the URL I am posting to is not one that I control, so I have no power over what it returns.

Thanks!