求教一小技巧方法，多谢！

求教一小技巧方法，谢谢！！！
求教一小技巧方法，谢谢！！！
有一组textbox，每个里面规定只能输入3个数字，我想实现每个在数满三个后光标自动移到下一个，另用方向键（上键和向左键一个功能，向下键和向右键一个功能）实现各个textbox间的焦点切换，谢谢！！！

[解决办法]
新建一工程，在窗体上画三个textbox，至于方向键不要用它，因为它有编辑文本框的功能，一般是用它在文本框内移动光标而用

Private Sub Text1_GotFocus()
Text1.DataChanged = False
End Sub

Private Sub Text1_KeyUp(KeyCode As Integer, Shift As Integer)
If Len(Text1.Text) = 3 And Text1.DataChanged = True Then '符合输入3个字符就跳过
SendKeys "{tab} "
End If

End Sub

Private Sub Text2_GotFocus()
Text2.DataChanged = False
End Sub

Private Sub Text2_KeyUp(KeyCode As Integer, Shift As Integer)
If Len(Text2.Text) = 3 And Text2.DataChanged = True Then
SendKeys "{tab} "
End If

End Sub

Private Sub Text3_GotFocus()
Text3.DataChanged = False
End Sub

Private Sub Text3_KeyUp(KeyCode As Integer, Shift As Integer)
If Len(Text3.Text) = 3 And Text3.DataChanged = True Then
SendKeys "{tab} "
End If

End Sub