jq的autocomplete接收的数据格式是怎样的？这样的格式不行的吗？

var availableTags = [{
                    "_C" : "000001",
                    "_S" : "SZZS",
                    "_N" : "上证指数",
                    "_T" : "指数",
                    "_F" : "3",
                    "_E" : "1001"
                },{
                    "_C" : "000002",
                    "_S" : "AGZS",
                    "_N" : "Ａ股指数",
                    "_T" : "指数",
                    "_F" : "3",
                    "_E" : "1001"
                }, {
                    "_C" : "000003",
                    "_S" : "BGZS",
                    "_N" : "Ｂ股指数",
                    "_T" : "指数",
                    "_F" : "3",
                    "_E" : "1001"
                }, {
                    "_C" : "000004",
                    "_S" : "GYZS",
                    "_N" : "工业指数",
                    "_T" : "指数",
                    "_F" : "3",
                    "_E" : "1001"
                }, {
                    "_C" : "000005",
                    "_S" : "SYZS",
                    "_N" : "商业指数",
                    "_T" : "指数",
                    "_F" : "3",
                    "_E" : "1001"
                }, {
                    "_C" : "000006",
                    "_S" : "DCZS",
                    "_N" : "地产指数",
                    "_T" : "指数",
                    "_F" : "3",
                    "_E" : "1001"
                }];
        $("#sk_keyword_ipt").autocomplete({
            source : availableTags,
            formatItem : function(data, i, total) {
                console.log("eeeee");
                return data._N + "   " + data._C + "  " + data._T ;
            },
            formatResult : function(data, i, total) {//结果格式
                return data._C+","+data._N;
            }
        });

上面的代码运行后会总是在dom中添加
<div style="display: none;">No search results.</div>
这样的隐藏的div，为什么？？
如果把availableTags这个变量改成下面那样就可以搜索，但是我的数据格式不是这样的，是和上面那样的，请问是哪里出错了吗？jq版本是v1.11.1

var availableTags = [
      "ActionScript",
      "AppleScript",
      "Asp",
      "BASIC",
      "C",
      "C++",
      "Clojure",
      "COBOL",
      "ColdFusion",
      "Erlang",
      "Fortran",
      "Groovy",
      "Haskell",
      "Java",
      "JavaScript",
      "Lisp",
      "Perl",
      "PHP",
      "Python",
      "Ruby",
      "Scala",
      "Scheme"
    ];

---

$( "#project" ).autocomplete({
      minLength: 0,
      source: projects,
      focus: function( event, ui ) {
        $( "#project" ).val( ui.item._C );
        return false;
      },
      select: function( event, ui ) {
        $( "#project" ).val( ui.item._C );

        return false;
      }
    })
    .autocomplete( "instance" )._renderItem = function( ul, item ) {
      return $( "<li>" )
        .append( "<a>" + item._C + "<br>" + item._S + "</a>" )
        .appendTo( ul );
    };

返回数据的格式错了，你可以参考下jquery ui的demo。