child locking the baby's door

well I guess today was the last straw, after fighting with the baby for almost an hour then finally getting him to sleep about an hour after that Dex decides to go in and wake him up, "because he wanted to say HI to him" well there goes mommy's little break. thank god for our rain forest swing and Thomas the train, they are doing good at keeping him quietly entertained. Thomas the train gets extra credit for keeping both boys "quiet". so is it wrong that I want to put one of those door knob childproof locks on the baby's bedroom door...I guess we'll see!