Of course, NS forces you to specify the extension on a file.
In case you hadn't heard, there have been many, many "exploits" or computer hacking techniques that take advantage of the fact that IE doesn't require this. I'm not going to debate the technical details or relative security of NS vs. IE, but as a general programming rule "strong typing" [specifying data types ) is a good idea unless you know *exactly* what your doing -- and most users simply don't. Why should they? They aren't programmers, and htey don't want to be