[eluser]TheFuzzy0ne[/eluser]
Yes, I think I understand better, thanks. But I still believe you don't need to submit any data that's already contained in the session, as it just adds further complexities.
Also, for downloading files - whilst you can't do this via Ajax, a simple link on the page which points at a controller method that will use
force_download(), (and doesn't output any other data), should work just as good as Ajax. The page shouldn't need to be refreshed, so you shouldn't need a separate window for the download. Unless of course the user is trying to access a file that doesn't exist, in which case your controller method will probably redirect the page.