Control your PDA's LED

I wrote a VB.NET class named LED to control PDA's LED.
我写了一个名为LED的类来控制PDA的LED灯。
Please see http://www.pocketpcdn.com/articles/led.html first to help understand the core of this class.
请首先阅读http://www.pocketpcdn.com/articles/led.html，这将有利于你理解这个类
And here is the class:
以下是这个类：

Imports System.runtime.InteropServices

And the test form is here:
这儿是用于测试窗体:

Imports System
Imports System.Collections
Imports System.Text