private async void MakePaymentButton_Click(object sender, EventArgs e) { employee = employees[EmployeesBox.SelectedIndex]; if (ValidatePaymenForm()) { PaymentModel payment = new PaymentModel() { PaymentAmount = CalculatePayment(employee), PaymentDate = DateTime.Now, EmployeeId = employee.Id }; await payment.AddPayment(); } else { MessageBox.Show("Проверьте правильность введенных данных", "Ошибка в заполнении формы", MessageBoxButtons.OK, MessageBoxIcon.Error); } }