Private Sub fehler(ByVal ex As Exception)
            Dim strace As New StackTrace(True)
            Dim count As Integer
            Dim indent As String = ""
 
            ' Low down the call stack, there are four stack frames
            Dim MethodName As String
            While count < strace.FrameCount
                Dim frame As New StackFrame
                frame = strace.GetFrame(count)
                MethodName &= frame.GetMethod().ToString() & _
                  frame.GetFileLineNumber().ToString() & ";" & vbCrLf
 
                indent = indent & "  "
                count = count + 1
            End While
            MessageBox.Show(ex.Message & vbCrLf & vbCrLf & vbCrLf & _
            MethodName)
        End Sub