VB计算器代码

Private Sub Command1_Click(Index As Integer)
Text1.Text = Text1.Text + Command1(Index).Caption
End Sub

Private Sub Command17_Click()
If Val(Text1.Text) = 0 Then
Text1.Text = ""
Else
Text1.Text = 1 / Val(Text1.Text)
End If
End Sub

Private Sub Command18_Click()
Text1.Text = Val(Text1.Text) * Val(Text1.Text)
End Sub

Private Sub Command2_Click()
a = Val(Text1.Text)
b = "+"
End Sub

Private Sub Command20_Click()
a = Val(Text1.Text)
b = "^"
End Sub

Private Sub Command21_Click()
If Text1.Text <> "" Then
Text1.Text = Left(Text1.Text, Len(Text1.Text) - 1)
End If
End Sub

Private Sub Command23_Click()
End
End Sub

Private Sub Command3_Click()
a = Val(Text1.Text)
b = "-"
End Sub

Private Sub Command4_Click()
a = Val(Text1.Text)
b = "*"
End Sub

Private Sub Command5_Click()
a = Val(Text1.Text)
b = "/"
End Sub

Private Sub Command7_Click()
Text1.Text = ""
End Sub

Private Sub Command8_Click()
Text1.Text = Text1.Text + "."
End Sub

怎么发了两个啊？