asp.netajax返回值的有关问题

$.ajax({

                        type: "GET",

                        url: "AjaxLogin.aspx",

                        dataType: "html",

                        data: "username=" + $("#<%=username.ClientID %>").val() + "&userpwd=" + $("#<%=userpwd.ClientID %>").val(),

                        beforeSend: function (XMLHttpRequest) {

                            //Pause(this,100000);

                        },

                        success: function (msg) {

                            $("#info").html(msg);

                            alert(msg);

                        },

                        complete: function (XMLHttpRequest, textStatus) {

                            //隐藏正在查询图片

                        },

                        error: function () {

                            //错误处理