This is a script I made thats a PM blocker. Here's what happens:

You get a PM
The script HIDES the Query Window until you consent
If you accept, it will open the window, and display the message
If you deny, it will close out the window, and tell the person whatever you set for the deny message

ON *:OPEN:?: {
  window -h $nick
  .msg $nick Stand By And Wait For Me To Answer This
  dialog -dm query query
  did -ra query 2 Message from $nick $+([,$1-,])
  .timerTL 1 60 msg $nick Sorry I Did Not Get To This Before Time Expired
  .timerx 1 61 dialog -x query query
  .timerc 1 62 window -c $nick
}
dialog query {
  title "Accpect/Decline Query"
  size -1 -1 400 200
  box "Nick/Message" , 1, 7 7 290 40
  edit "", 2, 10 23 285 20,read autohs
  button "Accept" , 15, 7 150 100 40, ok
  button "Decline" , 16,               150 150 100 40         150 150 100 40, cancel
}
on 1:dialog:query*:sclick:15:{
  .timertl off
  .timerx off
  .timerc off
  var %nick = $gettok($did(2),3,32)
  .msg %nick %acceptmsg
  window -w %nick
}
on 1:dialog:query*:sclick:16:{
  .timertl off
  .timerx off
  .timerc off
  var %nick = $gettok($did(2),3,32)
  msg %nick %denymsg
  window -c %nick
}

on *:LOAD:{
set %acceptmsg $$?="What do you want to tell people when you accept?"
set %denymsg $$?="What do you want to tell people when you deny?"
echo -a Thanks for loading the PM Blocker Script by Alex
echo -a Contact me on irc.authoritygamer.com:6660-6670.
echo -a You'll be able to find me.. I'm Head Operator there.
echo -a Hope this works for you!
}