It isn't. A comparison operator is NOT an English language conjunction - it
just looks like one!
The correct syntax is
If Me.txtItemID > 31 AND Me.txtItemID < 41 Then
Note that you had the greaterthan and lessthan operators reversed: even if you
had repeated Me.txtItemID, this would have opened the form only for txtItemID
values which are simultaneously less than 31 and also greater than 41. Of
course that can never happen! My suggested change will open the form for item
ID's 32, 33, 34, ..., 40, but not for 31 or less or for 41 or more.
John W. Vinson [MVP]