Scratch

So I got my Sokoban game working when dealing with only one "box" but when it gets to two boxes i dont know how to make him switch level to next ONLY after getting BOTH boxes in place. The whole idea of my project is when "Box" touches the "destination" it changes "level" variable by 1 moving on to next level but it just changes variable "level" forever when dealing with 2 boxes D:. Anyone can help me come up with a solution??
Will check out all your projects if respond 

link http://scratch.mit.edu/projects/DeAmouSE/2854257