Update textbox during typing - ms-access

Question

In Access, I have a form in which there are three textboxes.
I am trying to update a textbox called tbxCombinedName with a combination of both:
textbox tbxLastName (person's Last Name)
textbox tbxFirstName (person's First Name)
My question is: what textbox property do I use, so that as I am typing text in tbxLastName, the CombinedName textbox is updated immediately and thereafter saved in the table Contacts.
On Microsoft's website, I have found that the step processes when typing in a textbox are as follows:
KeyDown → KeyPress → BeforeInsert → Change → KeyUp
I've tried using the OnChange and OnKeyDown properties, but to no avail. Which property, combined with what code, will allow the update-as-you-type action to work?
This is what I wrote earlier, which didn't work:
Private Sub tbxLName_change()
Dim lastName As String
Dim nameCode As String
lastName = tbxLName.Value
Debug.Print lastName
nameCode = tbxNameCode.Value
nameCode = lastName
Debug.Print nameCode
End Sub
Thanks for all your help in advance.

Answer 1

This is one of the few cases where you should refer to the .text property.
In the Change event:
lastName = tbxLName.Text
The .text property is only available when a control has focus and it refers to the visible contents of the control.
However, this is a database and the general rule is that you no not store calculated fields. The full name can easily be obtained from a query.

Answer 2

Just a couple of notes:
You may want to go with KeyPress because it provides the ability to change or negate the key the user pushed.
In the example below, only letters are allowed and lower case letters are upper cased:
Private Sub tbxLName_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)
Const ASCII_LOWER_RANGE = 65
Const ASCII_UPPER_RANGE = 122
Const ASCII_LOWER_A = 97
Const ASCII_LOWER_Z = 122
Const UPPER_MODIFIER = -32
Const ASCII_CANCEL_CODE = 0
Select Case KeyAscii
Case ASCII_LOWER_RANGE To ASCII_UPPER_RANGE
If KeyAscii >= ASCII_LOWER_A And KeyAscii <= ASCII_LOWER_Z Then
KeyAscii = KeyAscii + UPPER_MODIFIER
End If
Case Else
KeyAscii = ASCII_CANCEL_CODE 'Cancel Key Press
End Select
End Sub