xbox_gamer1, use this one:

on !*:join:#:jp
on !*:part:#:jp 
alias -l jp {
  if $(,$+(%,jpon.,#)) {
    msg # $nick has $iif($event = join,joined,left) #
  }
}
on $*:text:/^!jp\so(n|ff)$/iS:#:{
  if !$nick(#,$nick,rv) && !%f {
    inc -u3 %f
    if $regml(1) == n {
      set $+(%,jpon.,#) $true
      .msg # xbox_gamer1's script is now switched on.
    }
    else {
      .msg # xbox_gamers1's join/part script is now switched off
      unset $+(%,jpon.,#)
    }
  }
}

It'll only respond to the channels where you have the command set for:

!jp on

!jp off

to turn the notice from a channel where you don't want the message shown.