Hashtable

This program is given in the following website. Following output is expected because elements are in this order in Add() method. But vice versa output of this order is returned. Please explain the reason. Problem is coloured. 

http://www.dotnetperls.com/dictionaryentry

1 = one
2 = two
3 = three

using System;
using System.Collections;

class Program
{
static void Main()
{
// Create hashtable with some keys and values.
Hashtable hashtable = new Hashtable();
hashtable.Add(1, "one");
hashtable.Add(2, "two");
hashtable.Add(3, "three");

// Enumerate the hashtable.
foreach (DictionaryEntry entry in hashtable)
{
Console.WriteLine("{0} = {1}", entry.Key, entry.Value);
}
Console.ReadKey();
}
}
/*
3 = three
2 = two
1 = one
*/