.NET Request/Reply Messaging Pattern

So im working on this project that has a request class and a replier class that i need to make a messaging pattern. However when I try and run it, it says the faul is that i dont have a main therefore i wont run it. Im Using Visual Studio 2015 to create the project and the code looks like this.

using System;
using System.Messaging;

public class Requestor
{
    private MessageQueue requestQueue;
    private MessageQueue replyQueue;

    public Requestor(String requestQueueName, String replyQueueName)
    {
        requestQueue = new MessageQueue(requestQueueName);
        replyQueue = new MessageQueue(replyQueueName);

        replyQueue.MessageReadPropertyFilter.SetAll();
        ((XmlMessageFormatter)replyQueue.Formatter).TargetTypeNames = new string[]{"System.String,mscorlib"};
    }

    public void Send()
    {
        Message requestMessage = new Message();
        requestMessage.Body = "Hello world.";
        requestMessage.ResponseQueue = replyQueue;
        requestQueue.Send(requestMessage);

        Console.WriteLine("Sent request");
        Console.WriteLine("\tTime:       {0}", DateTime.Now.ToString("HH:mm:ss.ffffff"));
        Console.WriteLine("\tMessage ID: {0}", requestMessage.Id);
        Console.WriteLine("\tCorrel. ID: {0}", requestMessage.CorrelationId);
        Console.WriteLine("\tReply to:   {0}", requestMessage.ResponseQueue.Path);
        Console.WriteLine("\tContents:   {0}", requestMessage.Body.ToString());
    }

    public void ReceiveSync()
    {
        Message replyMessage = replyQueue.Receive();

        Console.WriteLine("Received reply");
        Console.WriteLine("\tTime:       {0}", DateTime.Now.ToString("HH:mm:ss.ffffff"));
        Console.WriteLine("\tMessage ID: {0}", replyMessage.Id);
        Console.WriteLine("\tCorrel. ID: {0}", replyMessage.CorrelationId);
        Console.WriteLine("\tReply to:   {0}", "<n/a>");
        Console.WriteLine("\tContents:   {0}", replyMessage.Body.ToString());
    }
}

And the replier looks like this:

using System;
using System.Messaging;

class Replier {

    private MessageQueue invalidQueue;

    public Replier(String requestQueueName, String invalidQueueName)
    {
        MessageQueue requestQueue = new MessageQueue(requestQueueName);
        invalidQueue = new MessageQueue(invalidQueueName);

        requestQueue.MessageReadPropertyFilter.SetAll();
        ((XmlMessageFormatter)requestQueue.Formatter).TargetTypeNames = new string[]{"System.String,mscorlib"};

        requestQueue.ReceiveCompleted += new ReceiveCompletedEventHandler(OnReceiveCompleted);
        requestQueue.BeginReceive();
    }

    public void OnReceiveCompleted(Object source, ReceiveCompletedEventArgs asyncResult)
    {
        MessageQueue requestQueue = (MessageQueue)source;
        Message requestMessage = requestQueue.EndReceive(asyncResult.AsyncResult);

        try
        {
            Console.WriteLine("Received request");
            Console.WriteLine("\tTime:       {0}", DateTime.Now.ToString("HH:mm:ss.ffffff"));
            Console.WriteLine("\tMessage ID: {0}", requestMessage.Id);
            Console.WriteLine("\tCorrel. ID: {0}", "<n/a>");
            Console.WriteLine("\tReply to:   {0}", requestMessage.ResponseQueue.Path);
            Console.WriteLine("\tContents:   {0}", requestMessage.Body.ToString());

            string contents = requestMessage.Body.ToString();
            MessageQueue replyQueue = requestMessage.ResponseQueue;
            Message replyMessage = new Message();
            replyMessage.Body = contents;
            replyMessage.CorrelationId = requestMessage.Id;
            replyQueue.Send(replyMessage);

            Console.WriteLine("Sent reply");
            Console.WriteLine("\tTime:       {0}", DateTime.Now.ToString("HH:mm:ss.ffffff"));
            Console.WriteLine("\tMessage ID: {0}", replyMessage.Id);
            Console.WriteLine("\tCorrel. ID: {0}", replyMessage.CorrelationId);
            Console.WriteLine("\tReply to:   {0}", "<n/a>");
            Console.WriteLine("\tContents:   {0}", replyMessage.Body.ToString());
        }
        catch ( Exception ) {
            Console.WriteLine("Invalid message detected");
            Console.WriteLine("\tType:       {0}", requestMessage.BodyType);
            Console.WriteLine("\tTime:       {0}", DateTime.Now.ToString("HH:mm:ss.ffffff"));
            Console.WriteLine("\tMessage ID: {0}", requestMessage.Id);
            Console.WriteLine("\tCorrel. ID: {0}", "<n/a>");
            Console.WriteLine("\tReply to:   {0}", "<n/a>");

            requestMessage.CorrelationId = requestMessage.Id;

            invalidQueue.Send(requestMessage);

            Console.WriteLine("Sent to invalid message queue");
            Console.WriteLine("\tType:       {0}", requestMessage.BodyType);
            Console.WriteLine("\tTime:       {0}", DateTime.Now.ToString("HH:mm:ss.ffffff"));
            Console.WriteLine("\tMessage ID: {0}", requestMessage.Id);
            Console.WriteLine("\tCorrel. ID: {0}", requestMessage.CorrelationId);
            Console.WriteLine("\tReply to:   {0}", requestMessage.ResponseQueue.Path);
        }

        requestQueue.BeginReceive();
    }
}