Ajax内容：
$(document).ready(function () {
            $(function () {
                $("#submit").click(function () {
                    var name = $("#log").val();
                    var pwd = $("#pwd").val();

                    if (name.length == 0) {
                        alert("请输入用户名！");
                    }
                    else if (pwd.length == 0) {
                        alert("请输入密码！");
                    }
                    else {
                        $.post("../../Content/Handler.aspx", { mName: name, mPwd: pwd }, function (data) {
                            if (data == "right") {
                                window.location.href = "ManagerIndex.aspx";
                                //指定登录成功后你要转向的页面
                            }
                            else {
                                alert(data);
                            }
                        });
                    }
                });
            });
        });


再建一个Handler.aspx页面，后台写：

protected void Page_Load(object sender, EventArgs e)
        {
            string name = Request.Form["mName"].ToString();
            string pwd = Request.Form["mPwd"].ToString();
            if (name == "hu")
            {
                Response.Write("right");
                Response.End();
            }
            else
            {
                Response.Write("用户名或密码错误！");
                Response.End();
            }
        }


注意母版页的路径问题，最好将Handler.aspx页面放在Contents目录下