1- click on top of the cupboard (a little to the right) and get scissors.
2- click on blue cloth and get the first key (on the top right).
3- click next to the cupboard on the right side and get the 2nd key.
4- drag scissors to the cupboard to open it and you'll se the 3rd key.
5- drag the three keys to the door and the holes will disappear (you need to do this before getting the 4th key).
6- click on the pink cloth and get the 4th key.
7- drag the 4th key to the door and you're OUT!!!
Source: Escape Games 24