I found the following code snippet that will not allow a user to save a
worksheet until cell M2 has been populated:

Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)
If IsEmpty(Sheets("Sheet1").Range("M2").Value) Then
Cancel = True
MsgBox ("The workbook cannot be saved until cell M2 has been
populated.")
End If
End Sub

Being relatively new to VBA, can someone tell me how to modify the code
above so that a range (M2:M25) must be populated before a user is allowed to
save the worksheet?

I tried changing the 2nd code line above to:

If IsEmpty(Sheets("Sheet1").Range("M2:M25").Value) Then

but that didn't work. Any help would be greatly appreciated.

Thanks,
Bob