public int Create(Staff staff)
        {
            byte[] hashedBytes    = md5.ComputeHash(Encoding.ASCII.GetBytes(staff.Password));
            string hashedPassword = Encoding.ASCII.GetString(hashedBytes);

            staff.Password = hashedPassword;

            if (StaffDAL.GetByEmail(staff.Email) != null)
            {
                return(-1);
            }

            return(StaffDAL.Create(staff));
        }