private void GUIsubmit_Click(object sender, RoutedEventArgs e)
        {
            switch (get_action())
            {
            case "add":
                switch (get_view())
                {
                case "worker":
                    Console.WriteLine(DB.add_worker(user_name.Text, user_first_name.Text, user_last_name.Text, (user_date_of_birth.SelectedDate.HasValue ? (DateTime)user_date_of_birth.SelectedDate : DateTime.Now), int.Parse(user_worker_access.Text), CURRENT_USER).ToString());
                    break;

                case "client":
                    Console.WriteLine(DB.add_client(user_name.Text, user_first_name.Text, user_last_name.Text, (user_date_of_birth.SelectedDate.HasValue ? (DateTime)user_date_of_birth.SelectedDate : DateTime.Now), CURRENT_USER).ToString());
                    break;

                case "book":
                    Console.WriteLine(DB.add_book(book_name.Text, book_author.Text, book_category.Text, int.Parse(book_rating.Text), CURRENT_USER).ToString());
                    break;
                }
                break;

            case "remove":
                switch (get_view())
                {
                case "worker":
                    worker tempw = DB.delete_worker(user_name.Text, user_first_name.Text, user_last_name.Text, (user_date_of_birth.SelectedDate.HasValue ? (DateTime)user_date_of_birth.SelectedDate : DateTime.Now), int.Parse(user_worker_access.Text), CURRENT_USER);
                    if (tempw != null)
                    {
                        Console.WriteLine(tempw.ToString());
                    }
                    break;

                case "client":
                    client tempc = DB.delete_client(user_name.Text, user_first_name.Text, user_last_name.Text, (user_date_of_birth.SelectedDate.HasValue ? (DateTime)user_date_of_birth.SelectedDate : DateTime.Now), CURRENT_USER);
                    if (tempc != null)
                    {
                        Console.WriteLine(tempc.ToString());
                    }
                    break;

                case "book":
                    book tempb = DB.delete_book(book_name.Text, book_author.Text, book_category.Text, int.Parse(book_rating.Text), CURRENT_USER);
                    if (tempb != null)
                    {
                        Console.WriteLine(tempb.ToString());
                    }
                    break;
                }
                break;
            }

            GUI_clear();
        }