Force Mime Type in Browser (with Javascript)

Question

[I imagine that this is impossible due to security concerns, but:]

Is it possible to force the browser to handle a file with a certain mime type without controlling the server? I'm serving up files from file:// (on the client's machine itself) and I'd like to get text files to open in whatever their associated text editor is.

Note: Firefox just opens the file for viewing, which is not the desired behavior. I've tried changing the file extension even to something unknown, which does not help.

Answer 1

Nope, this is impossible, except maybe with IE and an ActiveX, but I seriously suggest you not to use it.