VB程序：统计子字符串在原字符串中出现的次数

Private Sub Command1_Click()
If Len(Text1.Text) = 0 Then
MsgBox "请输入原字符串内容："
Text1.SetFocus
ElseIf Len(Text2.Text) = 0 Then
MsgBox "请输入子字符串内容："
Text2.SetFocus
Else
Label3.Caption = "子字符串在原字符串中出现了：" & UBound(Split(Text1.Text, Text2.Text)) & "次"
End If
End Sub

s1=Text1.Text
s2=Text2.Text
msgbox "出现了：" & (len(s1)-len(replace(s1,s2,"")))/len(s2)