我想在文本框内实现每隔一秒出现一个字。试写了一个小程序，请帮忙修改。谢谢！
Private Sub Command1_Click()
Timer1.Enabled = True

End Sub

Private Sub Form_Load()
Text1.Text = ""

End Sub

Private Sub Timer1_Timer()
Dim i As Integer
For i = 1 To 4
a = Mid("狗年吉祥", i, i)
Next i
Text1.Text = Text1.Text + a

End Sub