最外面的IF为什么不能写else呢？写了程序也不执行？真的郁闷！ 
public void buyFilm(string filmname)//string filmname
        {
            Dictionary<string, Film> inventory = new Dictionary<string, Film>();
            foreach (string s in inventory.Keys)
            {
                if (s==filmname)
                {
                   if (inventory[s].Amount > 0)
                    {
                        inventory[s].Amount--;
                        break;
                    }
                    else
                    {
                        string ss = string.Format("《{0}》现在没货", filmname);
                        Console.WriteLine(ss);
                        break;
                    }
                }
              [color=FF00FF]  else
                {
                    string sr = string.Format("本店没有《{0}》", filmname);
                    Console.WriteLine(sr);
                    break;
                }[/color]            }
            writeFilms();
        }