I made this earlier for my bot, thought I'd share it here.

Enjoy!
Code:
on *:TEXT:!raffle:#:{
  if ($nick isop #) {
    set %raffle $rand(1,100)
    msg $chan /me First person to guess the number between 1 and 100 wins!
  }
}


on *:text:*:#: {
  if ($1- == %raffle) {
    msg $chan /subscribers  
    msg $chan /me Annnnnd $nick is the winner with the number %raffle $+ !!!!!!
    unset %raffle
    .timerraffle 1 10 msg $chan /subscribersoff
  }
  else { }
}