" wrote:
Thanks you have been very helpful - this appears to achieve what I was
trying to do.

You're welcome !

Is there a way using functions that allows the wt and id
values to be reset to null if the od is changed to a new value. I know
how to do this in code but was wondering if there where other options.

Don't think so, I'm afraid ..
--
Max
Singapore
http://savefile.com/projects/236895
xdemechanik
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