Mine

on *:TEXT:!dchan Icebot:#:{
  unset %scriptsactive. [ $+ [ $chan ] ]
  msg $chan Icebot v1.8 Deactivated Successfully.
}
on *:TEXT:!achan Icebot:#:{
  set %scriptsactive. [ $+ [ $chan ] ] on
  msg $chan Icebot v1.8 Activated Successfully.
}
on *:JOIN:#:{ 
  if ($nick == $me) { set %scriptsactive. [ $+ [ $chan ] ] on }
  else { notice $nick welcome $nick }
}