prev = function(e){
                var i = _index?_index-1:_size-1;
                var status = {
                    index: _index,
                    count: _size,
                    destination: i,
                    event:e
                };
                if(options.onChangeStart(status)!=false){
                    _api.setIndex(i);
                    options.onChangeEnd({index:i,count: _size});
                }
            }
jquery.tabs.js 1.0
http://jquerywidget.com