Christmas Eve and I have successfully assembled a desk chair for one of my daughters. It was easy! There is another chair for my other daughter, and unfortunately, there is a problem with the mechanism that raises andd lowers the seat. I know nothing about the mechanism, but it is a gas cylinder and the problem is that the pencil sized piston is coming out of the bottom of the cylinder when it isn't supposed to do that. It goes all the way to the floor and the mechanism to raise and lower the seat is not working. If anybody can provide some advice on how to fix this problem, it will make an 8 year old (and her father) very happy. Thank you!