Download data using Web Browser in asp.net

private void runBrowserThread(string url)
        {
            try
            {
                var th = new Thread(() =>
                {
                    var br = new WebBrowser();
                    br.DocumentCompleted += browser_DocumentCompleted;
                    br.Navigate(url);
                    Application.Run();
                });
                th.SetApartmentState(ApartmentState.STA);
                th.Start();
            }
            catch (Exception ex)
            {

            }
        }
#region - Browser Event -
        void browser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
        {           
            try
            {
                string Downloaddata = string.Empty;
                HtmlDocument doc = ((WebBrowser)sender).Document;
                HtmlElementCollection textboxes = doc.GetElementsByTagName("textarea");
                foreach (HtmlElement textbox in textboxes)
                {
                    Downloaddata = textbox.InnerText;
                    Downloaddata = Downloaddata + "";
                }
                File.WriteAllText("Give your path" + "file Name", Downloaddata);
            }
            catch (Exception ex)
            {

               
            }
        }