public static string AuthenticateUser(LoginViewModel model)
        {
            try
            {
                using (_certonaService = new CertonaServiceClient())
                {
                    try
                    {
                        var user = new UserDTO
                        {
                            UserID   = model.UserName,
                            Password = Encryption.GetMd5Sum(model.Password)
                        };
                        var request = new AuthenticateUserRequest {
                            User = user
                        };

                        AuthenticateUserResponse response = _certonaService.AuthenticateUser(request);
                        if (!response.Success)
                        {
                            return(Utilities.ParseServiceErrors(response.Errors));
                        }
                        if (response.User == null || response.User.UserID == null)
                        {
                            return("Invalid user account.");
                        }

                        var userDetailsRequest = new GetUserAccountApplicationFeaturesRequest {
                            User = response.User
                        };
                        var userDetailsResponse = _certonaService.GetUserAccountApplicationFeatures(userDetailsRequest);
                        if (userDetailsResponse.Success)
                        {
                            response.User.Accounts = userDetailsResponse.Accounts;
                        }

                        FormsAuth.SetAuthCookie(response.User, false);

                        ReportingStartDate = DateTime.Now.AddDays(-30);
                        ReportingEndDate   = DateTime.Now;
                    }
                    catch (TimeoutException exception)
                    {
                        _certonaService.Abort();
                        throw;
                    }
                    catch (CommunicationException exception)
                    {
                        _certonaService.Abort();
                        throw;
                    }
                }
            }
            catch (Exception ex)
            {
            }

            return("");
        }