Private Sub elapsetimer_Tick(sender As Object, _
                e As System.EventArgs) Handles elapsetimer.Tick
 
        lblElapsed.Text = string.empty
 
        With timetable
            For i As Integer = 0 To .Rows.Count - 1
                'Laufende Zeitmessung
                If IsDBNull(.Rows(i)("Ende")) Then
                    'Seit dem Start verstrichene Sekunden 
                    'in die Intervall-Spalte eintragen
                    Dim start As Date = DirectCast(.Rows(i)("Start"), Date)
                    Dim elapsed As New TimeSpan(Now.Ticks - start.Ticks)
 
                    .Rows(i)("Intervall") = elapsed.TotalSeconds
 
                    'Label für Anzeige der verstrichenen Zeit seit Start 
                    lblElapsed.Text = _
                    "Projekt-ID (" & .Rows(i)("ProjectID").ToString & "): " & _
                    elapsed.ToString("g")
                End If
            Next i
        End With
    End Sub