I am using Dropbox for Windows. I typically have all my files online-only, but when I am using some of them, I like to download the folder that they are in. I download it by using the 'Make Available Offline' feature. I don't want these files to stick around indefinitely. If I don't access these files for a while, will Dropbox make them online-only. Is there a way I can select the time frame in which to default them back to online-only? Do I have to manually set them back to online-only when I am done?