public IHttpActionResult PostCustomer(Customer customer)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            db.Customers.Add(customer);

            try
            {
                db.SaveChanges();
            }
            catch (DbUpdateException)
            {
                if (CustomerExists(customer.CustomerID))
                {
                    return Conflict();
                }
                else
                {
                    throw;
                }
            }

            return CreatedAtRoute("DefaultApi", new { id = customer.CustomerID }, customer);
        }
        // PUT api/Customers/5
        public IHttpActionResult PutCustomer(string id, Customer customer)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            if (id != customer.CustomerID)
            {
                return BadRequest();
            }

            db.Entry(customer).State = EntityState.Modified;

            try
            {
                db.SaveChanges();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!CustomerExists(id))
                {
                    return NotFound();
                }
                else
                {
                    throw;
                }
            }

            return StatusCode(HttpStatusCode.NoContent);
        }