Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!bu.edu!dartvax!Susan.A.Tenney
From: Susan.A.Tenney@dartmouth.edu (Susan A. Tenney)
Newsgroups: comp.sys.mac.hypercard
Subject: Re: Detecting Objects
Message-ID: <1991Mar19.133208.1225@dartvax.dartmouth.edu>
Date: 19 Mar 91 13:32:08 GMT
References: <17671@crdgw1.crd.ge.com>
Sender: news@dartvax.dartmouth.edu (The News Manager)
Organization: Dartmouth College, Hanover, NH
Lines: 16

In article <17671@crdgw1.crd.ge.com> leue@galen.crd.ge.com (Bill Leue) writes:

  Does anyone know of a "clean" way to detect the existance or non-existance
  of an object (like a button or field) from within a script?


If you're using HyperCard 2.0, you can use the "there is" operator, as in

  if there is a bg btn "Foo" then
    <blah blah>

If you're not using HyperCard 2.0, the Dartmouth XCMDs stack contains an XFCN
called ObjectExists that will do the trick.

Susan Tenney
Dartmouth College Computing Services