using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace EventsPractice
{
    public delegate void myEventHandler(string newValue);

    public class EventExample
    {
        private string _value;
        public event myEventHandler valueChanged;

        public string val
        {
            set
            {
                _value = value;
                valueChanged(_value);
            }
        }

        static void myEvt_valueChanged(string newValue)
        {
            Console.WriteLine("The value changed to {0}", newValue);
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using EventsPractice;

namespace EventsPractice
{
    public class Program
    {
        static void Main(string[] args)
        {
            EventExample myEvt = new EventExample();

            myEvt.valueChanged += myEventHandler(myEvt_valueChanged);

            string str;
            do
            {
                str = Console.ReadLine();
                if (!str.Equals("exit"))
                    myEvt.val = str;
            } while (!str.Equals("exit"));

        }
    }
}