I am trying to tab backwards in some textboxes on a UserForm when Shift
and Tab are pressed. I need to call another sub to validate the value
before I allow the user to exit the current textbox.

It works when the user tabs forwards, I use this code for that...

Private Sub TextBox2_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)
Select Case KeyAscii
Case 9: KeyAscii = 0: ntl 2
End Select
End Sub

(This calls my validation sub "ntl" and sends the number of the textbox
to it, in this example 2)

To tab backwards I am trying

Private Sub TextBox2_KeyDown(ByVal KeyAscii As MSForms.ReturnInteger,
ByVal Shift As Integer)
If Shift < 1 Then Shift = 0: Exit Sub
If KeyAscii = 9 And Shift = 1 Then ntlbak 2
End Sub

I want this to call my validation sub "ntlbak" and sends the number of
the textbox to it, in this example 2)

But this code does not do it. What am I missing?

Another probably connected problem,

I have noticed a very strange behaviour when I press the ctrl button a
few times, it really messes up the textbox and empties it after
seemingly tabbing the existing value around a little. Can this be
averted?

Garry Jones
Sweden