Try this
Code:
on *:text:*:#jokes:{
  if $network == Quakenet && $istok(JokeBot JokeOr MagicMan,$nick,32) {
    scid $$checknets(Undernet)
    if $me ison #jokes { msg $v2 $1- }
  }
  elseif $network == Undernet && $1 == !joke {
    scid $$checknets(Quakenet)
    if $me ison #jokes { msg $v2 $1- }
  }
}
alias checknets var %a | scid -at1 if ($network == $1) $(var %a = $cid,0) | return %a