jquery插件autocomplete问题

从服务端返回一个如下json字符串
[
{"DanWBH":1,"DanWMC":"神经科","DanWPYM":"SJK","DanWWBM":"","DanZBM":"0001"},
{"DanWBH":2,"DanWMC":"内科","DanWPYM":"nk ","DanWWBM":"","DanZBM":"0002"},
{"DanWBH":3,"DanWMC":"外科","DanWPYM":"wk   ","DanWWBM":"","DanZBM":"0003"},
{"DanWBH":4,"DanWMC":"消化科","DanWPYM":"xhk  ","DanWWBM":"","DanZBM":"0004"}
]

我在前台如下调用：
$("#fyks").autocomplete("serchKSJson", {
        minChars: 0,
        width: 310,
        matchContains: true,
        autoFill: false,
        formatMatch: function(row, i, max) {
            return row.DanWMC + " " + row.DanWPYM;
        },
        formatResult: function(row) {
            return row.DanWMC;
        }
    });


但是autocomplete返回结果是老是出现整个返回的json字符串。什么原因？

http://space.cnblogs.com/group/topic/3737/
这个链接和我说的问题一样。
有说用EVAL  我不知道在autocomplete的哪儿用eval?