Help with Procedure Please

[Paul]

First make the AirPortCode a combo box in the form and
limit to list =Yes.
Next:
On Not In List
Private Sub AirPortCode(or your field name)_NotInList
(NewData As String, Response As Integer)
MsgBox "That Aiport Code is not in our Database."
Response = acDataErrContinue
End Sub

Hope this helps,

Paul