c# - How to create and save a text file with JavaScript

Question

Do you know any cross-browser method to create and save a file with JavaScript on the client-side?

Considerations:

1. I can't save it on the server because the file is going to be read from a fiscal printer.
2. The server can't access the client. This is obvious because we are talking about a web application in the web, so the server can't access a client folder.
3. New ActiveXObject("Scripting.FileSystemObject"); is ONLY for Internet Explorer and even then not for all versions.
4. We are talking about printing on a fiscal printer, so I can't ask the cashier in the supermarket to download the text file and save it in a folder where the fiscal printer can read it.
5. If not JavaScript, what else can I use in my ASP, .Net 4.0, C# web application?

Answer 1

Basically, you said it, "we are talking about a web application." Do you know any web applications that save a file to your hard drive (besides cookies) without showing you a download prompt first?

Having said that, browsers have started to offer a persistence API that goes beyond cookies. (See, for example, this article.) But such a solution wouldn't meet your requirement of being cross-browser.