Private Sub combo1_KeyUp(ByVal KeyCode As Integer, ByVal Shift As Integer)
        Static sTextOld As String
        Dim I As Integer
        Dim sPos As Integer
 
        With combo1
            ' 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

 Private Sub ComboBox1_KeyUp(ByVal sender As Object, ByVal e As _
   System.Windows.Forms.KeyEventArgs) Handles ComboBox1.KeyUp
        If CType(sender, ComboBox).DropDownStyle = ComboBoxStyle.DropDown Then
            If e.KeyCode = Keys.Back OrElse e.KeyCode = Keys.Tab OrElse _
              e.KeyCode = Keys.Delete OrElse CType(sender, _
              ComboBox).Items.Count = 0 Then
                Return
            End If
            Static TextOld As String
            Dim I, pos As Integer
            With CType(sender, ComboBox)
                If TextOld <> .Text Then
                    For I = 0 To .Items.Count - 1
                        If .Items.Item(I).ToString.ToUpper Like _
                          .Text.ToString.ToUpper + "*" Then
                            TextOld = .Text
                            pos = .SelectionStart
                            .Text = .Items.Item(I).ToString
                            .SelectionStart = pos
                            .SelectionLength = .Text.Length - (.SelectionStart)
                            Return
                        End If
                    Next
                End If
            End With
        End If
    End Sub