This is just a game DEMO. I made this to help someone on the forums deal with multi-click layering issues. If you want to see how it was done, feel free to search for it on StencylForge (although it's easier to just search for "demo-" since I am the only one using that heading as of now).
Just click and drag. You'll need to reload the page to reset the puzzle (it IS a demo :P).