Mine

on *:load: {
  writeini AwaySystem.ini Away $me $ctime
  //echo -a Made by Jordie
}
on *:Text:*:#: {
  if (brb isin $1 || bbl isin $1) {
    if ($readini(AwaySystem.ini,Away,$address($nick,2)) == $null) {
      writeini AwaySystem.ini Away $address($nick,2) $ctime
      msg $chan $nick will $iif(brb isin $1,Be right back,be back later) $+ .
    }
  }
  elseif (back isin $1) {
    if ($readini(AwaySystem.ini,Away,$address($nick,2))) {
      var %gone = $readini(AwaySystem.ini,Away,$address($nick,2))
      msg $chan $nick $+ ! Welcome back! You've been gone for: $duration($calc($ctime - %gone))
      remini AwaySystem.ini Away $address($nick,2)
    }
  }
}