--------------------------------------------------------类文件里的
    public static void Chk_IsAdmin(string AdminId)
    {
        if (AdminId == null)
        {
            AdminId ="0";
        }
        string Temp1 = (string)AdminId;
        if (Temp1 == "0")
        {
            HttpResponse response = HttpContext.Current.Response;            response.Write("<" + "script>window.alert('超时或其他错误。');window.location.href='default.aspx';</" + "script>");
            response.End();
            
        }
    }
--------------------------------前台调用的
        ClsFun.Chk_IsAdmin(""+Session["AdminId"]);
------------------------------------
现在的问题是 没有弹出窗口!