Webclient upload file to ftp server

FernandoSoto,
As I mentioned in another thread. I follow your code to upload a file to ftp server by webclient at my web application. I pass a file path to the function you posted. I got a exception 'An exception occurred during a WebClient request.' even trying to access my local develope machine which is set as ftp server also.

The code is:
private void UploadToFtp(string zpath)
{
      try
                  {
                        // String array to hold the full path of each file to be transfered
                        // to the FTP site.
                        string[] UploadFiles ={zpath}; // null;

                        // The web site URL
                        string remoteURI = "ftp://10.10.99.75/";
                        // Load files to this subdirectory
                        string placeFileInFolder ="NewStore/"; // "uploadfolder/";
                        // Create the FTP client
                        WebClient ftpClient = new WebClient();
                        // The user name and password are stored here
                        NetworkCredential nc = new NetworkCredential("mylog", "mypassword");
                        ftpClient.Credentials = nc;
                        // used to check if there were any errors in transfering the files
                        Exception err = null;

                        for (int idx = 0; idx < UploadFiles.Length; idx++)
                        {
                              // Call the function to transfer the files to the FTP site
                              err = xfer(ftpClient, remoteURI + placeFileInFolder, UploadFiles[idx]);
                              // Check to see if there were any errors in the transfer
                              if (err != null)
                              {
                                    // Write the error somewhere and reset err to null for the next transfer
                                    Response.Write(err.Message);
                                    err = null;
                              }
                        }
                  }
                  catch (Exception e)
                  {
                        myParam.Text="ERROR";
                        this.ERRMSG.Text=e.Message;
                  }
            }
        // client is the FTP client, remoteFile is where on the site the file will be
        // stored, localFile is the full path to the file going to be transfered
        // to the FTP site.
        private Exception xfer(WebClient client, string remoteFile, string localFile)
        {
            Exception retErr = null;
            // Get the file name from the local file to name the file on the remote
            string filename = Path.GetFileName(localFile);
            // Add the file name that the file will be called on the FTP site.
            string WebResources = remoteFile + filename;
            try
            {
                // Transfer the file to the FTP site.
                client.UploadFile(WebResources, localFile);
            }
            catch (Exception ex)
            {
                // If any errors occurred report it to the caller.
                retErr = ex;
            }
            return retErr;
        }      

Please help