The Interface Construct in C#

using System;

namespace InterfaceDemo
{
	/// <summary>
	/// The BlueGUI is a form class using the IInput interface through the object input
	/// </summary>
	public class BlueGUI : System.Windows.Forms.Form
	{
		IInput input;

		public BlueGUI(IInput input)
		{
			this.input = input;
			this.BackColor = System.Drawing.Color.Blue;
			this.Show();
		}
		
		public void GetInput()
		{
			this.Text = input.NotifyOutput();
		}
	}
}