autocomplete 限制高度，超高启用scroll

    <style>
        .ui-autocomplete {
            max-height: 200px;
            overflow-y: auto;
            /* prevent horizontal scrollbar */
            overflow-x: hidden;
            /* add padding to account for vertical scrollbar */
            padding-right: 20px;
        }
    </style>

    <script>
        $("#text1").autocomplete({
            source: function (request, response) {
                $.ajax({
                    url: 'HttpHandler.ashx?todo=getData&term=' + request.term,
                    dataType: "json",
                    success: function (data) {
                        response($.map(data, function (Val) {
                            return {
                                label: Val.NAME,
                                value: Val.ID,
                                entity: Val
                            }
                        }))
                    }
                })
            }
            , minLength: 2
            , select: function (e, ui) {
                var Val= ui.item.entity;
                $("#text1").val(Val.ID);
                $("#text2").val(Val.NAME);
            }
        });
    </script>