Forums Scripts & Popups help on displaying mp3 size

$bytes($mp3(%mp3file).size,m3).suf)

1. $mp3 isn't a default mIRC alias, so we don't know what value it returns
2. Extra )
3. Are you trying to get the file size in the format "2.54MB"? If so use this:
$bytes($file(%mp3file).size,m3).suf