Redirect after form submit

How do I get a form to allow redirection after submit?

I've got a login form that should allow server redirection after a successful login, but this is not happening. I've already checked the response from server and it does contain the redirect address on the headers, but it is not been followed through.

Also, why adding the standardSubmit config to true makes the form submit to a .js url which obviously fails with a 404?

My form code is pretty simple:

Code:

form.submit({
    url: '/auth/',
    method: 'POST',
    params: data,
    standardSubmit: true // <-- makes form submit to a .js url which fails with a 404
});

Thanks.