public bool Update(int id, Customer cus)
        {
            try
            {
                using (ManageCustomersEntities ctx = new ManageCustomersEntities())
                {
                    var _ob = ctx.Customers.SingleOrDefault(b => b.ID == id);
                    if (_ob != null)
                    {
                        _ob.Name = cus.Name.Trim();
                        _ob.Phone = cus.Phone.Trim();
                        _ob.Email = cus.Email.Trim();
                        _ob.Address = cus.Address.Trim();
                        ctx.SaveChanges();
                    }
                }

                return true;

            }
            catch
            {
                return false;
            }
        }
 public bool Insert(Customer cus)
 {
     try
     {
         ManageCustomersEntities ctx = new ManageCustomersEntities();
         ctx.Customers.Add(cus);
         ctx.SaveChanges();
         return true;
     }
     catch
     {
         return false;
     }
 }
        public bool Delete(int id)
        {
            try
            {
                using (ManageCustomersEntities ctx = new ManageCustomersEntities())
                {
                    var _ob = ctx.Customers.SingleOrDefault(b => b.ID == id);
                    if (_ob != null)
                    {
                        ctx.Customers.Remove(_ob);
                        ctx.SaveChanges();
                    }
                }

                return true;

            }
            catch
            {
                return false;
            }

        }