/// <summary>
        /// Продать крупный бизнес
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void sellBig_Click(object sender, EventArgs e)
        {
            if (_bigBusiness != null)
            {
                _bigBusiness = null;

                Button_Text(buyBig, "Купить");
                Button_Enable(sellBig, false);
            }
        }
        /// <summary>
        /// Купить крупный бизнес
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void buyBig_Click(object sender, EventArgs e)
        {
            if (_bigBusiness == null)
            {
                _bigBusiness = new BigBusiness();

                Button_Text(buyBig, "Параметры");
                Button_Enable(sellBig, true);
            }
            else
            {
                var demandProfessionsForm = new Demand_Business("big");
                demandProfessionsForm.ShowDialog();
            }
        }