public async void Login()
        {
            if (Validate())
            {
                Account account = new Account();
                account = await _workService.GetAccount(Username, Password);

                if (account.Id != 0)
                {
                    Error = "";
                    //sla account id globaal op
                    Globals.AccountId = account.Id;
                    //ga naar volgende pagina
                    ShowViewModel <JobTabViewModel>(account);
                }
                else
                {
                    //foutmelding in lblErrorMessage
                    Error = "Username and password do not match";
                }
            }
            else
            {
                Error = "Username and password do not match";
            }
        }