//OK
 #region WindowActions
 private void Window_Closing(object sender, System.ComponentModel.CancelEventArgs e)
 {
     SearchStockWindow.instance = null;
 }
 public static SearchStockWindow ReturnInstance(List<Stock> Stocks, MainGUI main)
 {
     if (SearchStockWindow.instance == null)
         SearchStockWindow.instance = new SearchStockWindow(Stocks, main);
     return SearchStockWindow.instance;
 }