FTP Downloading a file while its upload is in progress

I have a windows service (VB.NET) which downloads files from a server a开发者_JAVA技巧fter a specific interval. What happens if it try to download a file when its upload is in progress?

If it creates some problem, how to cope with this situation?

Thanks, Imran

It depends on the implementation of the FTP server.
Most servers will probably throw an access denied exception when downloading the file, which you can catch. (Catch a WebException and look at the response and/or the status code)