autocomplete两个效果都没有

 <script type="text/javascript">
            $(function () {
                var arrUserName = ["王五", "刘明", "李小四", "刘促明", "李渊", "张小三", "王小明"];
                $("#textSearch").autocomplete(arrUserName,{
                    minChars: 0, //双击空白文本框时显示全部提示数据
                    formatItem: function (data, i, total) {
                        return "<I>" + data[0] + "</I>"; //改变匹配数据显示的格式
                    },
                    formatMatch: function (data, i, total) {
                        return data[0];
                    },
                    formatResult: function (data) {
                        return data[0];
                    }
                }).result(SearchCallback);
                function SearchCallback(event, data, formatted) {
                    $(".tip").show().html("您的选择是：" + (!data ? "空" : formatted));
                }
            });
        </script>