the first pic isnt the best screen but u can see how I used the edge of a wall shelf propped up against it to hold it on. It's a pretty tight fit anyways. originally I taped the top with 2 pieces of duct tape like a hinge but it didn't need it. I am replacing the screen top soon it was just a quick setup tank to house my male.
the 2nd and 3 pics are my other tanks. You can see how the shortest tank is keeping the screen top on the taller tank next to it and because it's shorter it allows air flow.
(the 3 middle tanks house my babies and juvenilles)
the end tank holds my plated leaf chameleon.
the last pic is my adult females home. It is also flipped on its side and is pushed up against the wall. the tank is wider than the wall so there is lots of good air flow still (as with the other flipped tanks) You can also see the white piece of corrigated plastic i added on the bottom inside of the screen to provide a barrier for the substrate.
hope this helps