Forms :: Deactivate Page Down Key?

I'm trying to deactivate the page down key in my form with no luck. How to deactivate the page down key. Here's the steps I have already completed.

I opened the form in design view, set KeyPreview Property to Yes, selected Database Tools, Visual Basic and inserted code in lines 3 through 9 after the dash / line.

Update_Total
'
'------------------------------------------------------------
Function Update_Total()
On Error GoTo Update_Total_Err
Private Sub form_keydown(KeyCode As Integer, Shift As Integer)
Select Case KeyCode
Case vbKeyPageDown

[code]....