create (with user authorization) local folder?

Hey All,
Is there any way (via java applet, javascript or php? maybe) to create a new folder, or prompt a user to create a new folder on the client machine -- say to "MyDocuments" perhaps with some kind of alert/warning like
Warning! This website is attempting to write files or folders to your system.
Do you wish to authorize? Ok, Cancel:p

You probably want to just make the file down loadable For one I don't think you are able to do this and also I doubt users would like it or dare come back to your site if you're trying to edit folders and such on their computer

Thanks ninnypants,
I should have prefaced that this is in the context of a subscriber-user web-app for home inspectors. My thought was -- when the user logged in to write a home inspection report -- the web app might create, or offer to create a customer_name folder for inspection photos under the user's My Documents/AI_Photos dir, where the web app would later look -- by default -- for any photos to upload (via java applet) into a customer specific report. In this context, I know for a fact that no one will complain. I suppose a download MIGHT be an option, but can you download an empty folder?