<input class="typeahead form-control" placeholder="Type a city" type="text" />

$('.typeahead').typeahead({
hint: true,
highlight: true,
minLength: 3,
limit: 8 }
, {
    source: function(q, cb) {
        return $.ajax({
            dataType: 'json',
            type: 'get',
            url: 'http://gd.geobytes.com/AutoCompleteCity?callback=?&q=' + q,
            chache: false,
            success: function(data) {
                var result = [];
                $.each(data, function(index, val) {
                    result.push({
                        value: val
                    });
                });
                cb(result);
            }
        });
    }
});