private void Add_Contract_Click(object sender, RoutedEventArgs e)
        {
            AddNewContract manage_Contracts = new AddNewContract();

            manage_Contracts.Show();
            Close();
        }
        // Добавление нового трудового договора
        private void AddNewContract_Click(object sender, RoutedEventArgs e)
        {
            var newContractWindow = new AddNewContract();

            newContractWindow.ShowDialog();

            if (!(bool)newContractWindow.DialogResult)
            {
                return;
            }

            _contractId     = newContractWindow.ContractId;
            _contractNumber = newContractWindow.ContractNumber;

            ContractTextBox.Text = _contractNumber;
        }