关于文件流的释放的疑问

Question

本人写了一个代码，通过流的操作，生成静态网页。目前的疑问是，各个流的释放顺序是否正确，以及是否完整？（特别是那个HttpWebRequest request不知道要不要释放它）。

局部代码如下：

using
{
               （此处省略了一些代码）
                do
                {
                    count = count + 1;
                    if (reader_toNewsData.HasRows)
                    {
                        HttpWebResponse response = null;
                        Regex reg1 = new Regex(@"(?<=.+/).+(?=\.aspx)", RegexOptions.IgnoreCase);
                        Match match1 = reg1.Match(sitePart_List[count]);
                        string staticFileHead = match1.Value;

                        while (reader_toNewsData.Read())
                        {
                            int siteID = reader_toNewsData.GetInt32(0);
                            string sitePath = siteHeader + sitePart_List[count] + "?id=" + siteID;
                            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(sitePath);
                            try
                            {
                                response = (HttpWebResponse)request.GetResponse();
                                Stream stream = response.GetResponseStream();
                                StreamReader reader = new StreamReader(stream);
                                string result = reader.ReadToEnd();
                                reader.Close();
                                stream.Close();
                                response.Close();

                                string savePath = Server.MapPath(@"Statesite\" + staticFileHead + siteID.ToString() + ".html");
                                StreamWriter writer = new StreamWriter(savePath, false, Encoding.UTF8);
                                writer.Write(result);
                                writer.Close();
                            }
                            catch (WebException e2)
                            {
                            }
                        }
                    }
                }
                while (reader_toNewsData.NextResult());
                reader_toNewsData.Close();
}

如果各位对代码的其他地方也有优化的建议，请不吝指教，谢谢！