private void btnCreateUser_Click(object sender, EventArgs e)
        {
            FrmAuthUser frm = new FrmAuthUser();

            if (frm.ShowDialog() == DialogResult.OK)
            {
                AuthUser user = AuthUser.CreateAuthUser();

                user.Username    = frm.Username;
                user.Password    = frm.Password;
                user.Description = frm.Description;
                user.Role        = frm.Role;

                BOUser current_user = AccountantPool.Instance.CurrentAccountant.User;
                current_user.SaveAuthUser(user);

                ViewModel();
            }
        }