jQuery 업로드 플러그인 Uploadify_jquery에서 Http 오류 302 오류를 해결하는 방법

<script>
$(document).ready(function() { 
   $('#file_upload').uploadify({ 
    'uploader' : 'uploadify/uploadify.swf', 
    'script'  : 'uploadify.php',
    'folder'  : 'uploads/file', 
    'formData': { 'session': '<&#63;php echo session_id();&#63;>'}, 
    'onComplete' : function(event, ID, fileObj, response, data) { 
     alert(response); 
    } 
   }); 
}); 
</script>

if (isset($_POST['session'])){ 
  session_id($_POST['session']); 
  session_start();//注意此函数要在session_id之后 
} 

protected void Application_BeginRequest(object sender, EventArgs e)
    {
      /* we guess at this point session is not already retrieved by application so we recreate cookie with the session id... */
      try
      {
        string session_param_name = "ASPSESSID";
        string session_cookie_name = "ASP.NET_SessionId";

        if (HttpContext.Current.Request.Form[session_param_name] != null)
        {
          UpdateCookie(session_cookie_name, HttpContext.Current.Request.Form[session_param_name]);
        }
        else if (HttpContext.Current.Request.QueryString[session_param_name] != null)
        {
          UpdateCookie(session_cookie_name, HttpContext.Current.Request.QueryString[session_param_name]);
        }
      }
      catch
      {
      }

      try
      {
        string auth_param_name = "AUTHID";
        string auth_cookie_name = FormsAuthentication.FormsCookieName;

        if (HttpContext.Current.Request.Form[auth_param_name] != null)
        {
          UpdateCookie(auth_cookie_name, HttpContext.Current.Request.Form[auth_param_name]);
        }
        else if (HttpContext.Current.Request.QueryString[auth_param_name] != null)
        {
          UpdateCookie(auth_cookie_name, HttpContext.Current.Request.QueryString[auth_param_name]);
        }

      }
      catch
      {
      }
    }

    private void UpdateCookie(string cookie_name, string cookie_value)
    {
      HttpCookie cookie = HttpContext.Current.Request.Cookies.Get(cookie_name);
      if (null == cookie)
      {
        cookie = new HttpCookie(cookie_name);
      }
      cookie.Value = cookie_value;
      HttpContext.Current.Request.Cookies.Set(cookie);
    }

<script type="text/javascript">
    var auth = "@(Request.Cookies[FormsAuthentication.FormsCookieName]==null &#63; string.Empty : Request.Cookies[FormsAuthentication.FormsCookieName].Value)";
    var ASPSESSID = "@Session.SessionID";

    $(function () {
      $('#upload').uploadify({
        'formData': { 'folder': '/Upload', 'ASPSESSID': ASPSESSID, 'AUTHID': auth },
        'buttonText': '浏览',
        'buttonClass': 'browser',
        'fileSizeLimit' : '100KB',
        'fileTypeExts': '*.xls;*.xlsx',
        'removeCompleted': false,
        'swf': '@Url.Content("~/Scripts/Uploadify/uploadify.swf")',
        'uploader': '/Upload',
        'onUploadSuccess': function (file, data, response) {}
      });
    });
  </script>