public string LoginSource(string user, string passcode)
        {
            string           resultJson  = "";
            var              crypto      = new SimpleCrypto.PBKDF2();
            Common           comm        = new Common();
            LoginUser_Result logindetail = new LoginUser_Result();

            using (var db = new Cconvert.Model.cconverterEntities())
            {
                var source = db.sourcemasters.FirstOrDefault(u => u.userid == user && u.active == true);
                if (source != null)
                {
                    if (source.loginrequired)
                    {
                        if (source.passcode == crypto.Compute(passcode, source.passwordsalt))
                        {
                            try
                            {
                                ObjectParameter token     = new ObjectParameter("token", typeof(string));
                                var             loginUser = db.LoginUser(user, source.passcode, token);
                                foreach (var s in loginUser)
                                {
                                    logindetail = s;
                                    break;
                                }
                                using (var conversion = new CConversion())
                                {
                                    resultJson = conversion.RetreiveToken(token.Value.ToString(), logindetail.userid);
                                }
                            }
                            catch (Exception ex)
                            {
                                resultJson = comm.GetErrorMessage("Some error occur");
                            }
                        }
                    }
                    else
                    {
                        resultJson = comm.GetErrorMessage("login not required ! please use your access key to fetch");
                    }
                }
                else
                {
                    resultJson = comm.GetErrorMessage("User does not exists");
                }
            }
            return(resultJson);
        }