public ActionResult Create(Certificate certificate)
        {
            if (!ModelState.IsValid)
            {
                return(View(certificate));
            }
            certificate.UserId = User.Identity.GetUserId();
            string certificatefilename      = Path.GetFileNameWithoutExtension(certificate.CertificateFile.FileName);
            string certificatefileextension = Path.GetExtension(certificate.CertificateFile.FileName);

            certificatefilename         = Guid.NewGuid() + certificatefileextension;
            certificate.CertificatePath = "~/Images/" + certificatefilename;
            certificatefilename         = Path.Combine(Server.MapPath("~/Images/"), certificatefilename);
            certificate.CertificateFile.SaveAs(certificatefilename);
            db.AddCertificate(certificate);
            ModelState.Clear();
            return(RedirectToAction("Index"));
        }