vb书管理系统

这个作业什么时候要呢？

Dim?n?As?Integer

Dim?sum?As?Double

sum?=?0

n?=?InputBox("请输入n的值")

For?i?=?1?To?n

sum?=?sum?+?jiecheng(i)

Next?i

Print?sum

End?Sub

Public?Function?jiecheng(ByVal?n?As?Integer)?As?Double

Dim?jc?As?Double

jc?=?1

For?i?=?1?To?n

jc?=?jc?*?i

Next

jiecheng?=?jc

End?Function