I grovel. Must you be so simply clear? LOL Indeed, I had already figured out that I must not use 'Thread' but I didn't know why. Thanks for pointing it out.

I had shifted to 'threads' and my code looked almost exactly like yours as I bagged the references and employed locking in both threads.

Thanks also for pointing out that the array would not be known yet and must be 'blessed' so to speak. I have it working now, on to the next lesson.

Seems the more I learn, the less I know.....grrrr!