Stupid, Disastrous Newbie Error

[Judy Perry]

Hi,

I don't know what dumb thing I just did, but whatever it was, in creating
and attempting to use a substack, my main stack now has no window (just
the Rev menu bar and environment.

Didn't delete the file -- I can still *see* the file, but what did I do
and can it be fixed?  Am trying to make a Harry Potter game for my nephew
(the one's available won't run on his machine) and am about to jump out a
window (well, not really, but...)

Gratefully,

Judy Perry