Interface in C#

Dear all the below code work and you give interface concept.

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System;

namespace InterfaceApplication

{

public interface ITransactions

{

// interface members

void showTransaction();

double getAmount();

}

public class Transaction : ITransactions

{

private string tCode;

private string date;

private double amount;

public Transaction()

{

tCode = " ";

date = " ";

amount = 0.0;

}

public Transaction(string c, string d, double a)

{

tCode = c;

date = d;

amount = a;

}

public double getAmount()

{

return amount;

}

public void showTransaction()

{

Console.WriteLine("Transaction: {0}", tCode);

Console.WriteLine("Date: {0}", date);

Console.WriteLine("Amount: {0}", getAmount());

}

}

class Tester

{

static void Main(string[] args)

{

Transaction t1 = new Transaction("001", "8/10/2012", 78900.00);

Transaction t2 = new Transaction("002", "9/10/2012", 451900.00);

t1.showTransaction();

t2.showTransaction();

Console.ReadKey();

}

}

}