I have a PO detail subform in a one-to-one relationship with a PO table. They are both displayed as form datasheet -- the detail is revealed by clicking on the '+'.
If the primary key of the PO already exists in the detail table I need the detail subdatasheet to open in edit mode; if the primary key of the PO doesn't exist in the detail table, I need the subdatasheet to open in addition mode (able to add a new record).
I don't know how to check the detail table for the PO key of the parent; I can open the form in acFormAdd but not in the subdatasheet, etc. Guidance please dear gurus.