How do i use foreach loop for ftpDirectory

You can't just get ftp listings from the Directory class: you have to set up an FTP connection first:

            FTPGetListing(@"Username", "Password", "ftp.Images.MyDomain.com");
...
        private void FTPGetListing(string user, string password, string ftpURL)
            {
            string strConnect = string.Format("ftp://{0}", ftpURL);
            FtpWebRequest ftp = (FtpWebRequest)FtpWebRequest.Create(strConnect);
            ftp.Credentials = new NetworkCredential(user, password);
            ftp.KeepAlive = false;
            ftp.Method = WebRequestMethods.Ftp.DownloadFile;
            ftp.UseBinary = true;
            ftp.Proxy = null;
            ftp.UsePassive = false;
            List<string> folders, files;
            FTPGetFolder(ftp, @"\", out folders, out files);
            // ...
            }
        private void FTPGetFolder(FtpWebRequest request, string baseFolder, out List<string> folders, out List<string> files)
            {
            request.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
            FtpWebResponse response = (FtpWebResponse)request.GetResponse();
            Stream responseStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(responseStream);
            string listing = reader.ReadToEnd();
            folders = new List<string>();
            files = new List<string>();
            string[] lines = listing.Split('\n', '\r');
            foreach (string line in lines)
                {
                ...
                }
            reader.Close();
            response.Close();
            }

[Edit]
Extra tags "</string></string>" removed.
[/Edit]