Detect if JavaScript is enabled in ASPX

 if (Session["JSChecked"] == null)
    //JSChecked -indicates if it tried to run the javascript version
    {
        // prevent infinite loop
        Session["JSChecked"] = "Checked";
        string path = Request.Url + "?JScript=1";
        Page.ClientScript.RegisterStartupScript(this.GetType(), "redirect", 
          "window.location.href='" + path + "';", true);
    }
    if (Request.QueryString["JScript"] == null)
        Response.Write("JavaScript is not enabled.");
    else
        Response.Write("JavaScript is enabled.");