When you include the word 'stack', I presume you mean that each one is totally visible and has a lower y-coordinate value than the one under it. But the title infers that you want them to occupy the same space. Not only is this vague, but in general, it would be difficult to help because of lack of information -- and the lack of any attempted code does not help to make things any clearer. Anyway, we cannot fix code that we cannot see to begin with.