Copy Paste - Subform

[K]

Hello,

I have a subform call frmRates. In this form I have a field called OD. On
Got Focus how do I program it to take the previous records OD number entered
by the user and copy it to the next record OD field?

 

[K]

Here is what I tried but it does not work


Private Sub OD_LostFocus()
If IsNull(OD) Then
OD = Forms!frmMain!frmRates!OD
End If

End Sub