' Autovervollständigung...
Private Sub cbo_firma_keydown(KeyCode As Integer, Shift As Integer)
Static sTextOld As String
Dim I As Integer
Dim sPos As Integer
    With cbo_firma
    ' nur wenn sich die Eingabe geändert hat
        If sTextOld <> .Text Then
            For I = 0 To .ListCount - 1
                If .List(I) Like .Text + "*" Then
                    sPos = .SelStart
                    sTextOld = .Text
                    .Text = .List(I)
                    .SelStart = sPos
                    .SelLength = Len(.Text) - sPos + 1
                    Exit For
                End If
            Next I
        End If
    End With
End Sub