// File#1 - FirstWindows.Form1.cs using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; namespace FirstWindows { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void Form1_FormClosing(object sender, FormClosingEventArgs e) { MessageBox.Show("Hope you are having fun!"); } } }