How to automatically re-enable Fiddle as system proxy?

I am running Fiddler as windows service and when I reset Internet options, Fiddler no longer acts as system proxy. Is there a way for Fiddler to detect changes in  proxy server and re-attach itself as system proxy?

This is what I tried

static function OnDetach() {

if (FiddlerApplication.oProxy.DetachedUnexpectedly)  { 
   FiddlerApplication.oProxy.Attach;

   }

}

Thanks in advance.