关于JQUERY+AJAX+JSON数据返回的问题，求高手找找原因。不是很熟悉

从后台记录的ASHX返加前台的JSON数据为：
[{"Id":"MQ==","PopCode":"511321198501306776","PopName":"刘XX","Gental":"1","Birthday":"2012-6-10","Level":"小学","SCharacter":"有过小手工技能培训","Memo":"小手工
护工等工作","CSCode":"刘家村","HandPhone":"13882252290","Address":"","Status":"0","UserId":"Admin","InputDate":"","WorkDate":"2008-6-10"},{"Id":"Mg==","PopCode":"511321198501306777","PopName":"刘家X","Gental":"1","Birthday":"","Level":"小学","SCharacter":"测试数据","Memo":"测试数据","CSCode":"刘家村","HandPhone":"13882252290","Address":"","Status":"0","UserId":"Admin","InputDate":"","WorkDate":""},{"Id":"Mw==","PopCode":"511321198501328776","PopName":"许诺","Gental":"1","Birthday":"1987-6-8","Level":"小学","SCharacter":"","Memo":"","CSCode":"刘家村","HandPhone":"13845672341","Address":"","Status":"1","UserId":"Admin","InputDate":"","WorkDate":""},{"Id":"NA==","PopCode":"511321198501328777","PopName":"王欢","Gental":"1","Birthday":"1987-6-8","Level":"小学","SCharacter":"","Memo":"","CSCode":"江湖社区","HandPhone":"13845672343","Address":"","Status":"0","UserId":"Admin","InputDate":"","WorkDate":""},{"Id":"NQ==","PopCode":"511321198501318777","PopName":"王倩","Gental":"0","Birthday":"1987-6-8","Level":"小学","SCharacter":"","Memo":"","CSCode":"刘家村","HandPhone":"13845672343","Address":"","Status":"0","UserId":"Admin","InputDate":"","WorkDate":""}]前台调用的JQUERY：<script src="JS/jquery-1.6.js" type="text/javascript"></script>下面是JS里JQUERY来接收后台ASHX发来的JSON数据代码：
。
$.ajax({
                type: "GET",
                url: "ASHX/handler3.ashx",
                data: "p=" + page + "&t=0&StrCategory=" + scategorystr,
                cache: false,
                dataType: "json",
                beforeSend: function() { $("#divload").show(); $("#jgcsTable").hide(); }, //发送数据之前
                complete: function() { $("#divload").hide(); $("#jgcsTable").show() }, //接收数据完毕
                success: function(msg) {
                alert(msg.root.length); //输出root的子对象数量                                         $("#jgcsTable").html("<table width='100%' border='0' cellspacing='0' cellpadding='0'><tr><th>姓名</th><th>性别</th><th>出生日期</th><th>文化程度</th><th>特长</th><th>就业意愿</th><th>培训情况 </th><th>就业情况</th></tr>");
                    $.each(msg.root, function(i,n) {
                                                $("#jgcsTable").append("<tr><a href='index3_con3.html' class='iframehtml2'><td>" + msg.PopName + "</td><td>" + msg.Gental + "</td><td>" + msg.Birthday + "</td><td>小学</td><td>吹千</td><td>耍</td><td>XX已培训</td><td>通过XX培训于XX时间就业</td></a></tr>");//                                            $("#jgcsTable").append(msg);
                        alert(msg);
                    });
                                        $("#jgcsTable").append("</table>");
                    ////                    if (page != 1)
                    ////                        $("#jgcsTable").hide();
                }
                //                error: function() { alert("对不起,页面出错了!"); }
            })
。。页面无错，脚本无错，但就是不能获取success: function(msg){}里从后台返回的数据。能在$("#jgcsTable").append里插入；固定数据，但不能取 msg[i].id,msg[i].PopName 等数据。用msg.id,msg.name也不能获取到。我对MSG。TOSTRING 显示：[OBJECT][OBJECT]什么情况？