Identify when internet connection redials

I have a program to store the external IP address of our network on our webserver.

Our internet connection in windows is set to re-dial everytime the connection is dropped.

How can I identify when it redials? I.e. I want to run my program every time windows redials the ISP.

Is there some kind of event I can use?

I guess my alternative will be to just run my program continually on a timer which will effectively refresh the IP address every 30 secs etc.


thanks
Kester