static void Main(string[] args)
{
Console.WriteLine("***Observer Pattern Demo***\n");
IObserver myObserver1 = new ObserverType1("Roy");
IObserver myObserver2 = new ObserverType1("Kevin");
IObserver myObserver3 = new ObserverType2("Bose");
Subject subject = new Subject();
subject.Register(myObserver1);
subject.Register(myObserver2);
subject.Register(myObserver3);
Console.WriteLine("Setting Flag = 5");
subject.Flag = 5;
subject.Unregister(myObserver1);
Console.WriteLine("\nSetting Flag = 50");;
subject.Flag = 50;
subject.Register(myObserver1);
Console.WriteLine("\nSetting Flag = 100");
subject.Flag = 100;
}