private void addVisitorBtn_Click(object sender, EventArgs e) { // creating and refencing a new visitor object Visitor visitor = this.createVisitor(); if (visitor != null) { // inserting visitor to the data grid view visitorController.insertVisitor(visitor); if (!File.Exists(visitor_file)) { // if a new file is created initialize its columns header "visitorid, firstname, lastname and so on" visitorController.initiateVisitorData(visitor_file); } if (visitor != null) { // populate data grid view this.insertToTable(visitor); // write into csv file visitorController.writeVisitorsData(visitor, visitor_file); // clears input fields in the form this.clearFields(); } } }