阅读以下程序，完成后面的题目：

Private Sub Command1_Click()

        Dim  N  As  Integer

        Dim  S  As  Integer

        N = val(Text1.Text)    

        S = 0

          For i = 1 To N

             S = S +  i * (i + 1)

          Next i

        Text2.Text = str(S)

End Sub