Automatic file upload from computer to web server

I need an application written in Visual Basic to automatically upload a chosen group of files and / or folders on a PC when they're changed, or at specified times. The program must upload via HTTP... the same way a file uploads from a web browser to a web site. It should be able to run in the background, but the user should have the ability to open it and see a progress bar or status while files are transferring and a history of what was transferred. The web server I have is already set up with a Perl script to accept uploads. This program I need will connect to that script. The program will need to let the user enter their username and password that will be verified by the Perl script before uploads can be accepted. The login information will be saved on their computer so the uploads can be automated.