如何为iPhone应用程序实现可达性

我正在开发一个使用Internet的iphone应用程序.因此，为了处理网络连接错误，我想使用可达性，但是从Apple网站api参考中，它指出构建和运行时需要iOS4，但我正在为iphone开发应用程序2克该版本最多仅支持iphone os 3.1.3.因此，任何人都可以帮助我实现可到达性类.

I am developing an iphone application which uses internet.So in order to handle the network connection errors i would like to use reachability,but from apple site api reference it states that build and runtime requires iOS4 but i am developing application for iphone 2g which only supports upto iphone os 3.1.3.So any one could help me in implementing the reachabilty class.

在此先感谢所有stackoverflow主机.....

Thanks in advance for all stackoverflow masters........