JScript does have a global scope. In regular JScript (WSH) you can just do "var global = this" in global scope then access it anywhere.
It definitely worked at some point, but use of it was removed/broken by Plus! in an update to the scripting engine.
I'm sure there was a reason but I sure as hell can't remember it
Maybe something to do with the event handling.
I know it worked because I made a script that allowed you to hook events or something like that, and my script broke
Edit: found it
[Beta-ish Utility Release] Hook System
So it was broken at some point between 2006 and now, lol.