How to Upload a Files to Ftp Server Without User Interaction?

Assuming your're using winforms or wpf you can use FileSystemWatcher

FileSystemWatcher fsw = new FileSystemWatcher("mydir");
fsw.Changed += new FileSystemEventHandler(fsw_Changed);
fsw.NotifyFilter = NotifyFilters.LastWrite;
fsw.EnableRaisingEvents = true;

The fsw will raise the event if the file is modified.
On the change-event, you can run your upload code and the notification in the tray or taskbar.

maybe you also want to use a filefilter like this

FileSystemWatcher fsw = new FileSystemWatcher("mydir", ".dat");