Yesterday you guys helped me with getting my seeds balance into the table with the my seeds used form.  I am now trying to update the same balance with my seeds bought.  When I the same method I get two entries in the SeedStockT Table, one from the form and one from the SQL.  I first tried to get around this by making my form unbound and only use the SQL but that didn't work. Next I tried to use SQL update but can't get that to work either. By refreshing the form before the update I tried to book the form data first and then run the SQL to get the balance in the table.

Here is the SQL:
Me.Refresh

Dim B
Dim NB
Dim LastD
        LastD = DMax("SeedDate", "SeedStockT", "ProductID=" & SaladTypeCombo.Column(0))
        B = DLookup("Balance", "SeedStockT", "ProductID=" & SaladTypeCombo.Column(0) & " And SeedDate=#" & LastD & "#")
        NB = B + SeedsBought
        
        
        DoCmd.RunSQL "UPDATE SeedStockT SET SeedStckT.Balance = " & VAL(NB) & " WHERE SeedStockT.ProductID= & SaladTypeCombo.Column(0) & " And SeedDate=#" & LastD & "#";

Any help again much appreciated.