gistfile1.js

YUI().use('autocomplete', 'jsonp', function (Y) {

var ac = new Y.AutoComplete({
    source: function (query, callback) {
        Y.jsonp('http://example.com/api/autocomplete?query=' + encodeURIComponent(query) + '&callback={callback}', {
            timeout: 10000 // 10 seconds,

            on: {
                success: callback,
                failure: function () { /* ... */ },
                timeout: function () { /* ... */ }
            }
        });
    }
});

});