on *:TEXT:!greets*:#:{ 
if ($nick isop $chan) {
    if ($2 == on) {
set $($+(%Greets.,$chan)) 
notice $nick Greets are now On for this channel.
}
    elseif ($2 == off) {
unset $($+(%Greets.,$chan)) 
notice $nick Greets are now Off for this channel.
}
    else { 
notice $nick You must be an Op in this channel.
    }
  }
}