Dim lnum As New List(Of Integer)
        For Each ctl As Control In Me.Controls
            If TypeOf ctl Is TextBox Then
                Dim tb As TextBox = CType(ctl, TextBox)
                Dim i As Integer
                If Integer.TryParse(tb.Text, i) Then
                    lnum.Add(i)
                Else
                    MsgBox(tb.Text & " ist kein Integer")
                    Return
                End If
            End If
        Next
        lnum.Sort()
 
        For Each i As Integer In lnum
            Debug.WriteLine(i.ToString())
        Next

Those people who think they know everything are a great annoyance to those of us who do - Isaac Asimov