public Form1() { InitializeComponent(); price = new BigStorePrice(); price.ProductPrice = numPrice.Value; PriceWatcher observer1 = new PriceWatcher("Observer 1"); price.Subscribe(observer1); observer1.PriceChanged += observer1_PriceChanged; PriceWatcher observer2 = new PriceWatcher("Observer 2"); price.Subscribe(observer2); observer2.PriceChanged += observer2_PriceChanged; }