Someone

menu Channel {
  Away:/gaway $??="Reason to be away"
  Back:/eaway
}
alias gaway {
  set %l $1-
  echo -a You are now away
  amsg I am away REASON: %l
}
alias eaway {
  echo -a You are now back
  amsg I am now back from being away REASON: %l
  unset %l
}