My Singleton in C#

//MySingleton
using System;
//SingletonPage Class
class SingletonPage
{
//FIElds
protected static SingletonPage checkoutpage;


//Constructor is protected to ensure Singleton
protected SingletonPage()
{
Console.WriteLine("if you see this line,then the only one instence is created!");
}

//Use this to Create SingletonPage instance
public static SingletonPage NewCheckOutPage()
{
if (checkoutpage==null)
checkoutpage= new SingletonPage();
return checkoutpage;
}

};
//-------------------------------------End of SingletonPage Class


//TestApp
class TestApp
{
public static void Main(string[] args)
{
Console.WriteLine("'create' pagea:");
SingletonPage pagea=SingletonPage.NewCheckOutPage();

Console.WriteLine("'create' pageb:");
SingletonPage pageb=SingletonPage.NewCheckOutPage();

Console.WriteLine("'create' pagec:");
SingletonPage pagec=SingletonPage.NewCheckOutPage();

Console.WriteLine("'create' paged:");
SingletonPage paged=SingletonPage.NewCheckOutPage();

while(true){}
}
};