use the same format that the 8ball used
Code:
on ^*:text:!catch*:#:{
  haltdef
  if ($2- == on && $nick isop $chan) { set %pokemon true | msg $chan pokemon now active }
  elseif ($2- == off && $nick isop $chan) { unset %pokemon | msg $chan Pokemon now off }
  elseif (%pokemon) {
    .msg $chan $nick caught a $read(pokemon.txt)
  }
  else .msg $chan Sorry Pokemon catch is off
}