a hook and eye cabin lock.
Good, not all of you would think I was some evil mother.
We put it on to keep our crawling baby out of his big brothers room which is full of lego and playmobil. The door won't actually shut properly on its own. My older boy actually has the door open when he goes to bed as hes going through that phase.
Am having a big party and loads of people will see it and I even thought of putting a note on the door explaining it.