Could you precisely explain your problem based on "what you want to achieve" and "what the problems are", sorry but I'm a little confused right now.
The previous problem was the scrolling icon appearing when clicking middle mouse.
The code you gave me disabled completely middle mouse interactions, so it solved the problem but prevented the game from using the MMB.
So i found a new code that works just fine (disables the scrolling icon, but allows to use MMB on objects).
this one: "document.body.onmousedown = function(e) { if (e.button === 1) return false; }"
Now, the only issue is not really a big deal, i just need to know if there is a "global" form/ID for button objects as well (like "body" for other objects), so i dont need to assign a formID to all the 100+ buttons in my projects