求教一道VB题目：设计程序，当给定n值时，求出S=1+(1+2)+(1+2+3)+…+(1+2+3+…n)的值。

Private Sub Command1_Click() Dim N As Integer Dim S As Integer N = InputBox("输入N的值", "提示") If N 0 Then For i = 1 To N For j = N To 1 Step -1 S = S + i * j Next Next MsgBox "S=" &