Allow User to Download File using Ajax

Question

I am looking for a way to allow users to download a file from my site using ajax. The reason why i need to do this is because the files are quite big (50 megs normally). So

Answer 1

I don't really see how you can allow a user to download a file using ajax. There won't be any way to get the file to their filesystem from javascript. What's wrong with targeting the file into an iframe or a new window and letting users manage the download like they are used to using their browser?