This is what I need to happen when I entered the aircraftId and clicked the menu to record the aircraftID the data I placed in the CarrierName textbox should also be recorded, so when I highlight the aircraftID in the listbox along with the aircraftID appearing in it's textbox the CarrierName shold appear in it's textbox.
Dim carrierNameByAircraftIDList as New SortedList
Private Sub mmuRecordSaveArrival_Click(...) Handles mmuRecordSaveArrival.Click
'Add the carrier name to the list indexed by aircraft ID.
Private Sub lstAircraftID_SelectedIndexChanged(...) Handles lstAircraftID.SelectedIndexChanged
Me.txtAircraftID.Text = Me.lstAircraftID.SelectedItem
'Retrieve the carrier name for the selected aircraft ID.
Me.txtCarrierName.Text = carrierNameByAircraftIDList(Me.lstAircraftID.SelectedItem)