If you don't believe me, go see for yourself at this link: http://www.oldapps.com/mirc.php?old_mirc=45?changelog
Version History of mIRC 6.0
- Added /tnick command, changes to a temporary nickname without affecting your main and alternate nickname settings.
- Added $awaymsg and $awaytime to return away status when used with $away identifier.
They were all added for the same version.
Actually the $away identifier has to be added before 6.0. as mentioned, "when used with $away identifier." The /tnick command is already there in 6.0 and you've just missed it.
Unless you used a version before 6.0 was introduced when you made this snippet, then it's understandable if you weren't aware of the /tnick command.
But then again, everybody can lie through their teeth and say I made it using 5.8 or older; there is just no way to prove otherwise.