问如何在asp.net中编写重定向应用？

EN

void Application_BeginRequest(object sender, EventArgs e)
    {
        string url = Request.Url.ToString().ToLower();
        string from = ConfigurationSettings.AppSettings["from"];
        if (url.IndexOf(from) >= 0)
        {
            url = url.Replace(from, ConfigurationSettings.AppSettings["to"]);
            Response.Redirect(url);
        }
        else
        {
            if (url.IndexOf("error.aspx") < 0)
            {
                Response.Redirect("Error.aspx?url=" + Server.UrlEncode(url));
            }
        }
    }