阶乘在VB 中怎么写呀

建一个Command1。中间那部分就是运算程序。代码如下。＝＝＝＝＝＝＝＝＝＝＝＝＝Private Sub Command1_Click()Dim a As Integer, i As Integer, s As Doubles = 1a = InputBox("输入数")For i = 2 To as = s * iNextMsgBox a & "的阶乘是：" & sEnd Sub