主题：向上向下代码的问题？

Select Case e.Sender.Name

    Case "上一条"

        CurrentTable.Position = CurrentTable.Position - 1

    Case "下一条"

        CurrentTable.Position = CurrentTable.Position + 1

    Case "最前"

        CurrentTable.Position = 0

    Case "最后"

        CurrentTable.Position = CurrentTable.Rows.Count -1

End Select

不能连续向上或向下，代码应该怎么改部，求老师指点下"?万谢