Jquery Ajax 操作javascript全局变量

var str; /*   载入留言  */
var loadguest = function() {
    $.ajax({
        url: '/Ashx/GetMsgs.ashx',
        type: "GET",
        data: { page: page },   //  第几页
        dataType: 'json',
        beforeSend: function() {
        },
        error: function() {
            ;
        },
        success: function(msg) {
            $("#contact_msg").empty();
            if (msg != "0") {
                var data = msg.table;
                str = "";
                $.each(data, function(i, n) {
                    str += "<table width='100%' border='1' cellpadding='0' cellspacing='0' class='msg_table'>";
                    str += "<tr>";
                    str += "<td width='20%' rowspan='3' align='center' valign='top' class='tr_img'><p class='msg_ID'>ID:" + n.ID + "</p>";
                    str += "<img class='msg_headimg' src='" + n.Head + "' width='100' height='100'/><br/>";
                    str += "<span class='msg_name'>" + n.CustName + "</span><br/>";
                    str += "<span class='msg_ip'>" + n.IP + "</span></td>";
                    str += " <td width='80%' height='20' valign='middle'><span class='msg_title'>" + n.Title + "</span><span class='msg_date'>" + n.Dt + "</span></td>";
                    str += "</tr><tr>";
                    str += "<td height='120' valign='top' class='msg' id='msg_id" + n.ID + "'><p>" + n.Content + "</p>";
                    GetMsgRly(n.ID);   //通过留言记录的ID去查询对应的回复，对str进行读写
                    str += "<div id='msg_rly" + n.ID + "' class='rly'><textarea name='textarea' id='textarea" + n.ID + "' cols='45' rows='5'></textarea>";
                    str += "<a href=';' title='点击回复' onlick='Submit(" + n.ID + ")'>回复</a> <a href=';' title='取消回复' onclick='CancelRly(" + n.ID + ")' id='Cancel" + n.ID + "'>取消</a> </div></td>";
                    str += "<tr><td height='20' valign='middle'><a href='#' title='点击和我聊天' class='msg_a'><img src='images/oicq.gif' /></a> <a href='#' title='点击给我发邮件' class='msg_a'><img src='images/email.gif' /></a> <a href='#' title='点击访问我的网站' class='msg_a'><img src='images/home.gif' /></a> <span class='msg_manager'> <a name='" + n.ID + "' href=';' title='点击回复该留言' onclick='ShowRly(" + n.ID + ")' class='msg_a'><img src='images/reply.gif' /></a> <a name='" + n.ID + "' href=';' title='点击删除该留言信息' onclick='DeleteMsg(" + n.ID + ")' class='msg_a'><img src='images/recycle.gif' /></a> </span></td>";
                    str += "</table>";
                });
                $("#contact_msg").append(str);               
            }
            else {
                ;
            }

 

        }
    })
}

/*   加载留言回复内容  */

var GetMsgRly = function(MsgID) {
    $.ajax({
        url: '/Ashx/GetMsgRly.ashx',
        type: "GET",
        data: { MsgID: MsgID },
        dataType: 'json',
        beforeSend: function() {

        },
        error: function() {
            ;
        },
        success: function(rly) {
            if (rly != "0") {
                var rlydata = rly.table;
                rlystr = "";
                $.each(rlydata, function(i, r) {

                   /*   在这里对str进行操作离开该方法之后对str的操作就丢失了，但是实际上对应内容能够读写出来，用alert（）能显示内容*/
                    str += "<span class='Msg_rly'><span class='Msg_rly_line'></span>";
                    str += "<span class='msg_rly_manager'>管理员回复：</span><br/>";
                    str += "<span class='Msg_rly_content'>" + r.Content + "</span> ";
                    str += "<span class='Msg_rly_Dt'>于" + r.Dt + "</span></span>";
                });                
            }
        }
    });

}