You would probably do better to implement this via a DocumentBeforeClose macro, coded along the lines of:
Code:
Private Sub wdApp_DocumentBeforeClose(ByVal Doc As Document, Cancel As Boolean)
Const StrNm As String = "Home_Attempt_1_Date"
If Doc.FormFields(StrNm).Result = "N/A" Then _
If MsgBox(StrNm & " is N/A." & vbCr & "Continue closing?", vbYesNo) = vbNo Then _
Cancel = True
End Sub
For implementation instructions, see:
http://word.mvps.org/FAQs/MacrosVBA/AppClassEvents.htm
Note also how much simpler the code can be made (even if you don't use this event)
Alternatively, see:
http://word.mvps.org/faqs/macrosvba/...eforeClose.htm