GUI Windows Forms C# Tutorial

using System;
using System.Windows.Forms;
public class MainClass {
    public static void Main() {
        DialogResult dr = MessageBox.Show("Do you want to create a new file?",
                                          "WonderWord",
                                          MessageBoxButtons.YesNoCancel,
                                          MessageBoxIcon.Question);
        if (dr == DialogResult.Yes) {
            // "Yes" processing
        } else if (dr == DialogResult.No) {
            // "No" processing
        } else {
            // "Cancel" processing
        }
    }
}