Ok,
I got past this with the following code:
Code:
Private Sub updateVars()
LotFilter = Nz(Forms!Reports_Form!Reports_Subform!LotFilter, "")
End Sub
Thank you to everyone who looked at this.
Reports_Subform = the name I gave to the subform in the properties window.
Reports_Sub = the name that I used previously. This is what that sub is called in the Access Objects list on the Left. (Not used, this is what my problem was)
Reports_Form = the name of the parent form from the Objects list on the left. There is no name in the properties window to use in its place.