BoxPosition = Dmax(Nz("BoxPosition","PHIMS/OpenELIS Clinical Specimen Numbers","BoxID = " & Me.Parent.BoxID),0))+1
BoxPosition = Nz(DMax("BoxPosition", "PHIMS/OpenELIS Clinical Specimen Numbers", "BoxID = " & Me.BoxID), 0) + 1
BoxPosition = Nz(DMax("BoxPosition", "PHIMS/OpenELIS Clinical Specimen Numbers", "BoxID = '" & Me.BoxID &"'"), 0) + 1
There is a single quote ' when the criteria are alphanumeric