public bool employee_registration(Employee employee)
        {
            Regex GmailRegex, IdRegex, userRegex;

            GmailRegex = new Regex(@"^[a-z0-9](\.?[a-z0-9]){5,}@g(oogle)?mail\.com$");
            IdRegex    = new Regex(@"^[0-9]{1}-[0-9]{4}-[0-9]{4}$");
            userRegex  = new Regex(@"^.*?(?=@)");

            if (Regex.IsMatch(employee.employee_id, IdRegex.ToString()))
            {
                if (Regex.IsMatch(employee.employee_email, GmailRegex.ToString()))
                {
                    Match username = Regex.Match(employee.employee_email, userRegex.ToString());
                    employee.employee_username = username.ToString();
                    EmployeeDatabase edbDatabase = new EmployeeDatabase();
                    edbDatabase.EmployeeRegistration(employee);

                    return(true);
                }
                else
                {
                    return(false);
                }
            }
            else
            {
                return(false);
            }
        }