Is it okay to use emoticons in a manuscript?

In my scene, both of my characters are having an internet chat and one character is using an emoticon. How should I describe that? Or should I just keep that part of the scene out altogether?|||It's fine. Just type it the way you would online. (But leave the chatspeak to a minimum).|||It's fine as long as you make it clear that it's only for the internet-speak aspect of the story.|||no