VB计算 1-1/3!+1/5!-1/7!+……+（-1)^（n-1)/(2n-1)!请填空

VB计算 1-1/3!+1/5!-1/7!+……+（-1)^（n-1)/(2n-1)!请填空
Private Sub Command1_Click()
Dim i As Integer,j As Integer
Dim n As Integer
Dim s As Double
j=1
s=1
n = Val(Text1.Text)
For i = 2 To n
j=__________ '计算1/（2*i-1)!
s=_______________' l累加通项式
Next i
text2.text=str(s)