Nz("")
Use NZ and dlookup prior to adding the record.
Example:
Dim intRec as Integer
intRec = nz(dlookup("FieldName","tblName","[RMA_ID]=12345"),0)
If intRec > 0 then
'There is a record
else
'Code to add the record
end if
I use this trick all the time. Hopefully you'll understand.