protected void LogToFile()
{
        string logFilePath = Server.MapPath("Trace.txt");

        StreamWriter sw = new StreamWriter(logFilePath, true);

        //true means if file not there then create it otherwise append to it.

        try
        {
            sw.WriteLine("Logging Time: " + DateTime.Now.ToLongDateString());

            sw.WriteLine("OS/Browser/Version : "+Request.Browser.Platform.ToString()+"/" 
+ Request.Browser.Browser.ToString()+ “/"+Request.Browser.Version.ToString());
           
            if (Request.UrlReferrer != null)
            {
                sw.WriteLine("Referrer: "+ Request.UrlReferrer.ToString());
            }

            sw.WriteLine("User Agent: " + Request.UserAgent.ToString());

            sw.WriteLine("---------------------------------------------------");
        }
        catch(Exception )
        {
        }
        finally
        {
            if (sw != null)
            {
                sw.Close();
            }
        }  
    }