EXTJS 资料 Ext.Ajax.request 获取返回数据

下面是一个登陆页面调用的EXTJS

login function，通过  url: '/UI/HttpHandlerData/Login/Login.ashx',获取返回登陆账户和密码！

Ext.onReady(function () {

    login = function (target) {
        if (eval(document.getElementById('TxtUserName')).value == "") {
            alert("提示! 请输入账户!"); return false;
        }
        else if (eval(document.getElementById('TxtPassword')).value == "") {
            alert("提示!请输入密码!"); return false;
        }
        else {
            var username = eval(document.getElementById('TxtUserName')).value;
            var password = eval(document.getElementById('TxtPassword')).value;

            Ext.Ajax.request({
                url: '/UI/HttpHandlerData/Login/Login.ashx',
                method: 'POST',
                clientValidation: true,
                waitMsg: '正在提交数据...',
                waitTitle: '提示',
                params: {
                    username: username,
                    password: password
                },
                success: function (response) {
                    var data = Ext.decode(response.responseText);
                    //设置Cookie
                    new Extjs.cookie.set(data.userid, data.username);
                    window.location.href = "../Page/InformationManagement/Index.html";
                },
                failure: function () {
                    Ext.Msg.alert("提示", "登陆失败，请与管理员联系！");
                }
            });
        }
    }
});

后台代码：

这是在一般处理程序中的代码：

  public void ProcessRequest(HttpContext context)
        {

            string username = context.Request.Form["username"];
            string password = context.Request.Form["password"];
            int intUserID = ;
            DataSet ds = saBLL.Login(username, password);

            //客户端输出变量
            string strResult = string.Empty;
            if (ds.Tables[].Rows.Count > )
            {
                //用户不存在
                if (ds == null)
                    strResult = "{success:true,flag:false,msg:'用户不存在!'}";
                //用户密码不正确
                else if (ds.Tables[].Rows[]["Password"].ToString() != password)
                    strResult = "{success:true,flag:false,msg:'用户密码不正确!'}";
                //正确
                else
                {
                    intUserID = Convert.ToInt32(ds.Tables[].Rows[]["AccountId"].ToString());
                    strResult = "{success:'true',flag:'true',userid:'" + intUserID + "',username:'" + ds.Tables[].Rows[]["LoginName"] + "'}";
                }
            }
            else
            {
                strResult = "{success:true,flag:false,msg:'用户不存在!'}";
            }

            //客户端输出
            context.Response.Write(strResult);

        }