lexical scoping confusion

["Russell Y. Webb" <rw20@...>]

I've managed to get confused about lexical scoping and am away from my 
normal computer so I can't test this out.  What happens if you return a 
subfunction that accesses local variables in the outer function's 
scope?  Something like this:

function outer()
	local x = 0
	function inner()
		x = x + 1
		print(x)
	end
	inner() -- should print "1"
	return inner
end

x = 12
f = outer()
f() -- what does this do?  runtime error?
print(x) -- I assume this prints "12"

Thanks,
Russ