Here is a very simple example:
	Code:
	using System;
using System.Windows.Forms;
using System.Drawing;
	
public class MyEventHandler : Form
{		
	public MyEventHandler()
	{
		// Just setup a very very simple UI
		Size = new Size(200, 200); // Size of window
		
		// Create new button with the created window as parent
		Button myButton = new Button();
		myButton.Parent = this;
		myButton.Text = "Click me";
		// When button is clicked, run OnButtonClick
		myButton.Click += new EventHandler(OnButtonClick);
	}
	
	// Display message box when button has been clicked
	public void OnButtonClick(object sender, EventArgs e)
	{
		MessageBox.Show("You clicked me");
	}
	
	public static void Main()
	{
		Application.Run(new MyEventHandler());
	}
}