Originally Posted by Bruno Campanini

The small routine I added (Private Sub Workbook_SheetChange())
works that way:
every time you change a value in a A:J range of the sheet, the code
checks the D cell for zero value and sends a message.

It's not practical: may be you want D cell to be checked after completion
of A:C range, or something like that.
You didn't give enough info...

Bruno