Something

on *:TEXT:!whois*:#: {
  if ($nick isop $chan || $nick ishop $chan) { 
    if ($2 == on) {
      if (%whois [ $+ [ $chan ] ] != on) {
        set %whois [ $+ [ $chan ] ] on
        msg $chan Whois on join has been enabled for $chan by $nick $+ .
      }
      else {
        notice $nick Whois on join is allready on for $chan $+ . | halt
      }
    }
    elseif ($2 == off) {
      if (%whois [ $+ [ $chan ] ] == on) {
        set %whois  [ $+ [ $chan ] ] off
        msg $chan Whois on join has been disabled for $chan by $nick $+ .
      }
      else {
        notice $nick Whois on join is allready off for $chan $+ .
      }
    }
  }
}
on *:JOIN:#: {
  if (%whois [ $+ [ $chan ] ] == on) {
    set %whoisnick $nick
    set %whoischan $chan
    whois $nick
  }
  else {
    halt
  }
}
raw *:*: { 
  if (%whoisnick && %whoischan) {
    if ($numeric == 319) { 
      msg %whoischan %whoisnick is currently on: $3- 
      unset %whoisnick
      unset %whoischan 
    }
  }
  else {
    halt 
  }
}