VBA UNIT CHANGE

Hello, 
I wont to change ruler units from inches to millimeters and use this code:

Sub UnitChange()
Application.Unit = cdrMillimeter
Application.Refresh
End Sub

Sub UnitChange1()
ActiveDocument.Unit = cdrMillimeter
Application.Refresh
End Sub



But this code not work. No error returned, but unit not changed.
Any suggestion will be accepted gratefully.

Greetings!