Make Document as Readonly upon opening

[atzdgreat]

hello there. I saw a post about making the workbook as readonly upon opening

Private Sub Workbook_Open()
    ActiveWorkbook.ChangeFileAccess Mode:=xlReadOnly, WritePassword:=""
    MainWindow.Show
End Sub

how about in Word Document?

Private Sub Document_Open()
    ActiveDocument.ChangeFileAccess Mode:=xlReadOnly, WritePassword:="" 'This doesn't work.
    MainWindow.Show
End Sub