Something

alias greets {
  if ($1 == on) { set %sgreet on | echo -a * Greets are now on | return Greets = On }
  elseif ($1 == off) { set %sgreet off | echo -a * Greets are now on | return Greets = Off }
  else { echo -a * 4It's gotta be either 12On 4or 12Off 4dude. }
}
on *:TEXT:!Defgreet*:#: {
  set %greet [ $+ [ $address ] ] $2-
  /notice $nick Your greet is now: $2- 
}
on *:TEXT:!Delgreet:#: {
  if (%greet [ $+ [ $address ] ] == $null) { /notice $nick You can't delete your greet! You don't even have one! }
  else unset %greet [ $+ [ $address ] ]
  /notice $nick You greet has been deleted!
}
on *:JOIN:#: {  
  if (%sgreet == on) { /msg $chan  [12••1 $nick 12••1]  %greet [ $+ [ $address ] ]  }
  else { }
}