调用下载函数下载到了我的页面？
哪位大虾帮我看一下这个下载方法。怎么用vs调试时可以争取下载文件，用iis时就把我的页面个下载过来了。怎么避免下载我的页面？

public static bool DowndLoadFile(string _fileName, string _fullPath, long _speed)
  {
  if (!File.Exists(_fullPath))//文件不存在
  {
  System.Web.HttpContext.Current.Response.Write("<script language='javascript'>alert('文件不存在，下载失败');</script>");
  return false;
  }
  try
  {
  System.Web.HttpRequest request = System.Web.HttpContext.Current.Request;
  System.Web.HttpResponse response = System.Web.HttpContext.Current.Response;
  FileStream myFile = new FileStream(_fullPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
  BinaryReader br = new BinaryReader(myFile);
  try
  {
  response.AddHeader("Accept-Ranges", "bytes");
  response.Buffer = false;
  long fileLength = myFile.Length;
  long startBytes = 0;
  int pack = 10240; //10K bytes
  double sleepnum = 1000 * pack / _speed;


  //int sleep = 200; //每秒5次 即5*10K bytes每秒
  int sleep = (int)Math.Floor(sleepnum) + 1;
  if (request.Headers["Range"] != null)
  {
  response.StatusCode = 206;
  string[] range = request.Headers["Range"].Split(new char[] { '=', '-' });
  startBytes = Convert.ToInt64(range[1]);
  }
  response.AddHeader("Content-Length", (fileLength - startBytes).ToString());
  if (startBytes != 0)
  {
  response.AddHeader("Content-Range", string.Format(" bytes {0}-{1}/{2}", startBytes, fileLength - 1, fileLength));
  }
  response.AddHeader("Connection", "Keep-Alive");
  response.ContentType = "application/octet-stream";
  response.AddHeader("Content-Disposition", "attachment;filename=" + System.Web.HttpUtility.UrlEncode(_fileName, System.Text.Encoding.UTF8));

  br.BaseStream.Seek(startBytes, SeekOrigin.Begin);
  double num = (fileLength - startBytes) / pack;
  int maxCount = (int)Math.Floor(num) + 1;

  for (int i = 0; i < maxCount; i++)
  {
  if (response.IsClientConnected)
  {
  response.BinaryWrite(br.ReadBytes(pack));
  System.Threading.Thread.Sleep(sleep);
  }
  else
  {
  i = maxCount;
  }
  }
  }
  catch (Exception ex)
  {
  CreateErrorLog(ex);
  return false;
  }
  finally
  {
  br.Close();
  myFile.Close();