Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!rex!mandel@vax.anes.tulane.edu
From: mandel@vax.anes.tulane.edu (Jeff E Mandel MD MS)
Newsgroups: comp.sys.mac.hypercard
Subject: Lock Screen causes consternation!
Message-ID: <5840@rex.cs.tulane.edu>
Date: 24 Jan 91 14:04:11 GMT
Sender: news@rex.cs.tulane.edu
Organization: Tulane University School of Medicine
Lines: 31

This may just be a reflection of the fact that I don't read manuals completely,
but I seem to be having problems as a result of Lock Screen in HC 2.0 (I don't
yet have v2). I have a project (for scheduling procedures in the operating
room) which spans multiple stacks - one which contains most of the scripts, all
XCMDs and resources, and which changes almost never, one which is an empty
shell which is cloned and into which data for a given day is loaded by CL/1,
and one which contains data applicable to all days, which evolves over time.
This permits me to refine the code stack without having to worry about all
those data stacks that people have created. The problem is that occasionally it
is necessary to pop oer to another stack to read or write some data. Naturally,
I would prefer to Lock Screen to avoid user confusion:

on getData
	global theData
	Lock Screen
	push cd
	go to cd "dataCard" of stack "dataStack"
	put cd fld "theData" into theData
	pop cd
	Unlock Screen
end getData

Now without the Lock Screen, this works flawlessly, however, with Lock Screen,
in some (but not all) cases fails with a "No such field" type error. When this
happens, the problem is always fixed by removing the Lock Screen. Is this the
way this is supposed to work, or is this a bug?

Jeff E Mandel MD MS
Asst Professor of Anesthesiology
Tulane University School of Medicine
New Orleans, LA