Build HTML FROM ASPX

private static void Rebuild(String dir,String url,String FileName)
{
    Encoding code = Encoding.GetEncoding("utf-8");
    StreamReader sr = null;
    StreamWriter sw = null;
    string str = null;

    WebRequest temp = WebRequest.Create(url);
    WebResponse myTemp = temp.GetResponse();
    sr = new StreamReader(myTemp.GetResponseStream(), code);
    try
    {
        sr = new StreamReader(myTemp.GetResponseStream(), code);
        str = sr.ReadToEnd();
    }
    catch(Exception ex)
    {
        throw ex;
    }
    finally
    {
        sr.Close();
    }

    str = str.Replace("FAQstyle.css","../FAQstyle.css");
    try
    {
        sw = new StreamWriter(System.Web.HttpContext.Current.Server.MapPath(dir+"/") + FileName, false, code);
        sw.Write(str);
        sw.Flush();
    }
    catch(Exception ex)
    {
        throw ex;
    }
    finally
    {
        sw.Close();
    }

}