public async Task<IHttpActionResult> PutCellPhone(int id, CellPhone cellPhone)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            if (id != cellPhone.Id)
            {
                return BadRequest();
            }

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

            try
            {
                await db.SaveChangesAsync();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!CellPhoneExists(id))
                {
                    return NotFound();
                }
                else
                {
                    throw;
                }
            }

            return StatusCode(HttpStatusCode.NoContent);
        }
        public async Task<IHttpActionResult> PostCellPhone(CellPhone cellPhone)
        {
            if (!Request.Content.IsMimeMultipartContent())
            {
                return BadRequest();
            }
            if (HttpContext.Current.Request.Files.Count > 0 &&
                HttpContext.Current.Request.Files[0].ContentLength > 0)
            {
                HttpPostedFile fileData = HttpContext.Current.Request.Files[0];

                string extention = Path.GetExtension(fileData.FileName);

                if (string.Equals(".xls", extention) || string.Equals(".xlsx", extention))
                {
                    string temp_path = HttpContext.Current.Server.MapPath(
                        string.Format("~/Images/{0}{1}", Guid.NewGuid(), extention));

                    fileData.SaveAs(temp_path);
                    cellPhone.ImageUrl = temp_path;
                }
            }
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }
            db.CellPhones.Add(cellPhone);
            await db.SaveChangesAsync();

            return CreatedAtRoute("DefaultApi", new { id = cellPhone.Id }, cellPhone);
        }