Untitled

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
        MainMenu mainMenu = new MainMenu();
        MenuItem fileMenuItem = mainMenu.MenuItems.Add("&File"); // Renamed "File" to "fileMenuItem"
        fileMenuItem.MenuItems.Add(new MenuItem("&Open")); // Renamed "open" to "Open"
        this.Menu = mainMenu;
    }
}