public void XoaLM(string MLM)
        {
            CafeEntities cf = new CafeEntities();
            LOAIMON      lm = new LOAIMON();

            lm.MALOAIMON = MLM;
            cf.LOAIMONs.Attach(lm);
            cf.LOAIMONs.Remove(lm);
            cf.SaveChanges();
        }
        public void ThemLM(string MLM, string TLM)
        {
            CafeEntities cf = new CafeEntities();
            LOAIMON      lm = new LOAIMON();

            lm.MALOAIMON  = MLM;
            lm.TENLOAIMON = TLM;
            cf.LOAIMONs.Add(lm);
            cf.SaveChanges();
        }