Got it!
Does turn out that most of the suggestions I've seen on boards don't
really apply to POST as much as they do to GET.
But after diving back through the API (and a little time at the
bookstore) I figured it out.
This works like a charm for a form with a regular [input type=submit]
button with [form id=subscribeform]:
$('subscribeform').addEvent('submit', function(e) {
new Event(e).stop();
$('subscribeform').set('send', {
url: '/lists/?p=subscribe&id=2',
method: 'post',
onFailure: function() {
alert('fail!');
},
onRequest: function() {
alert('on req');
},
onSuccess: function(responseText, responseXML) {
$('newsletter-content').set('html', responseText);
},
onStateChange: function() {
alert('on change');
}
});
$('subscribeform').send();
});
Hope this is useful for someone with the same problem.