private void ConfirmOweButton_Click(object sender, RoutedEventArgs e) { if (Utility.TextHasNoData(this.CompanyBox) || Utility.TextHasNoData(this.HowMuchTextBox) || Utility.TextHasNoData(this.WhyMoneyOwedTextBox) || Customer == null) { MessageBox.Show("Input all fields"); return; } // Create the finance and upload it Finance finance = new Finance { FinanceCustomer = Customer, FinanceOwe = HowMuchTextBox.Text, FinanceDescription = WhyMoneyOwedTextBox.Text }; FinanceManager.AddFinance(finance); (new MainWindow()).Show(); this.Close(); }