vb中弹出无效外部过程

Private Sub Command1_Click()
Dim a As Double
Dim b As Double
Dim r As Double
a = Val(Text1.Text)

b = Val(Text2.Text)
r = Val(Text3.Text)

If b = 0 Then
MsgBox "被除数不能为零"
ElseIf b <> 0 Then
r = a / b
End If
End Sub

Private Sub Form_Load()
Print "欢迎使用"
End Sub

Private Sub Command1_Click()

Dim a, b, r As Double
a = Val(Text1.Text)
b = Val(Text2.Text)

If b = 0 Then
MsgBox "被除数不能为零"
ElseIf b <> 0 Then
r = a / b
End If
Text3.Text = r
End Sub

Private Sub Form_Load()
Print "欢迎使用"
End Sub

你的窗体上应该画有三个文本框，并且名字分别是Text1、Text2、Text3，否则就会出现这个错误。