simple AJAX

ajax.js

var ajax = function(uri, cb) {
	var xhr = new XMLHttpRequest();
	//xhr.withCredentials = true; // uncomment to send cookies and stuff
	xhr.open('POST', uri, true); // GET OR POST...
	var cbInner = function() {
		if (xhr.readyState === 4 && xhr.status === 200) {
			return cb(null, JSON.parse(xhr.response));
		}
		cb('error requesting ' + uri);
	};
	xhr.onload  = cbInner;
	xhr.onerror = cbInner;
	xhr.send(null);
};