screen math, stacks, fields, and effective screenRect

[Dr. Hawkins]

I'm trying to figure out screen math to set the top of a helper stack to
the top of a field, and the like.

The math doesn't seem to make sense.

It would *seem* to me that
   the top of this stack + the top of me

should give the top of the field in screen coordinates.

But it doesn't

So I tried effective rect and the like.

How can the effective top of a stack be *smaller* than the stack itself
(higher on the screen).  Shouldn't it be greater due to the window
handle/bar, whatever that is?

-- 
Dr. Richard E. Hawkins, Esq.
(702) 508-8462