Thanks Gail & Craig for your input,

Would use of the TIMESTAMP data type be of any help? As I understand it, it is used for version-stamping table rows. I have not tried it yet, but an UPDATE could go ahead WHERE ID = specificID AND LOGTIMESTAMP = SpecificTimeStamp. If the record is changed while another user had it in edit mode the Update would generate an error. Will try it and report.

John