async void OnDelete(object sender, EventArgs args)
        {
            try {
                ServiceReference4.ExpenseCategoryModel payment = new ServiceReference4.ExpenseCategoryModel();

                payment.id = Int32.Parse(id.Text);
                var wsPayment = new ServiceReference4.ExpenseCategorySoapClient();
                wsPayment.DeleteAsync(payment.id);
                wsPayment.DeleteCompleted += wsPaymentDeleteCompleted;
            } catch (Exception ex) {
                throw ex;
            }
        }
        async void OnSubmitData(object sender, EventArgs args)
        {
            try {
                ServiceReference4.ExpenseCategoryModel payment = new ServiceReference4.ExpenseCategoryModel();

                payment.detail = detail.Text;

                var wsPayment = new ServiceReference4.ExpenseCategorySoapClient();
                wsPayment.AddAsync(payment);
                wsPayment.AddCompleted += wsPaymentAddCompleted;
            } catch (Exception ex) {
                throw ex;
            }
        }