Make + And - Adjust Date In Field

I am trying to make the + - (numpad) adjust the date of the current text field. The problem I am having is I believe the input mask intercepts the keypress and my keypress event is never fired. Here is my code:

Code:
Private Sub LeaseDate_KeyDown(KeyCode As Integer, Shift As Integer)If (KeyAscii = 107) Then
LeaseDate = DateAdd("d", 1, LeaseDate)
End If
If (KeyAscii = 109) Then
LeaseDate = DateAdd("d", -1, LeaseDate)
End If
End Sub

Access makes the ding noise when I try and press + and - ...