A dialog takes time and isn't something I'll write. If you want to make one, you can read /help dialogs to see how.

Instead, here's a quick right click method:

Code:
on *:text:*:*: {
  if (lol isin $1- && %play.sound == On) {
    splay $findfile($mircdir\lol\,*.wav,$rand(1,$findfile($mircdir\lol\,*.wav,0)))
  }
  elseif (hi isin $1- && %play.sound == On) {
    splay $findfile($mircdir\hello\,*.wav,$rand(1,$findfile($mircdir\hello\,*.wav,0)))
  }
}

on *:input:*: {
  if (lol isin $1- && %play.sound == On) {
    splay $findfile($mircdir\lol\,*.wav,$rand(1,$findfile($mircdir\lol\,*.wav,0)))
  }
  elseif (hi isin $1- && %play.sound == On) {
    splay $findfile($mircdir\hello\,*.wav,$rand(1,$findfile($mircdir\hello\,*.wav,0)))
  }
}

menu * {
  Sounds
  .$iif(%play.sound == On,Turn Sounds Off,Turn Sounds On): $iif(%play.sound == On,set %play.sound Off,set %play.sound On)
}


Just right click to turn the sounds On/Off.