find duplicate record in pop up form

[deb]

First I will explain the form setup...
Main form called fKPIEdit, has subform called fKPIEditDetails (linked by
KPIID)
Within the subform there are buttons for each KPI. The buttons open a pop
up form called fKPIDetailNotePopUP so the user can enter the KPI Note (keys
are KPIID and KPIListID)

IF the user clicks the button for KPI1 and there is a note already in the
table called tKPIDetailNote (keys are KPIID and KPIListID) for KPI1, I need a
msgbox to say it is a dupe record and close the pop up form else just open
the pop up form for user to enter the note.

Please help