Bound records have controls with a Value property, the default property, and
an OldValue property. If you chnge the existing record, the Value is the
change, until the record is saved. Try using the BeforeUpdate event instead
of the Change event, which fires at each keystroke. The BeforeUpdate event
of the textbox fires when you leave that textbox. The BeforeUpdate event of
the record occurs before you leave the record or form. The OldValue property
is maintained until the record is saved. You might try something like this
in the BeforeUpdate event of the form: (air code)

Sub Form_BeforeUpdate (Cancel As Integer)
   If Me.txtAddress = Me.txtAddress.OldValue Then
       Me.txtAddressChange = Me.txtAddress
   Else
       Me.txtAddressChange = ""
   End If

' Do the same for each value you want to capture
End Sub

To capture the Old Value, simply add the .OldValue property to Me.txtAddress