Nulstil formular

Er der nogen der kan sige mig hvorfor min kode ikke virker? Jeg vil gerne nulstille samtlige 'controls' in min formular:

Private Sub cmdReset_Click()
Dim frm As Form, ctl As Control
Set frm = Screen.ActiveForm
   
For Each ctl In frm
  Select Case ctl.ControlType
       
            Case acTextBox
                ctl = ""
            Case acComboBox
                ctl = ""
            Case acListBox
                ctl = ""
            Case acOptionGroup
                ctl = Null
            Case acCheckBox
                ctl = Null
            Case acOptionButton
                ctl = Null
    Next ctl
   
End Sub