(AzureCXP) fixes sample

resolves MicrosoftDocs/azure-docs#47976

Author: mikeurnun

articles/service-bus-messaging/service-bus-dotnet-get-started-with-queues.md

@@ -200,6 +200,7 @@ To receive the messages you sent, create another **Console App (.NET Core)** app
 1. In *Program.cs*, add the following `using` statements at the top of the namespace definition, before the class declaration:
 
     ```csharp
+    using System;
     using System.Text;
     using System.Threading;
     using System.Threading.Tasks;
@@ -216,18 +217,23 @@ To receive the messages you sent, create another **Console App (.NET Core)** app
 
     Enter your connection string for the namespace as the `ServiceBusConnectionString` variable. Enter your queue name.
 
-1. Replace the default contents of `Main()` with the following line of code:
+1. Replace the `Main()` method with the following code:
 
     ```csharp
-    public static async Task Main(string[] args)
-    {    
+    static void Main(string[] args)
+    {
+        MainAsync().GetAwaiter().GetResult();
+    }
+
+    static async Task MainAsync()
+    {
         queueClient = new QueueClient(ServiceBusConnectionString, QueueName);
 
         Console.WriteLine("======================================================");
         Console.WriteLine("Press ENTER key to exit after receiving all the messages.");
         Console.WriteLine("======================================================");
 
-        // Register the queue message handler and receive messages in a loop
+        // Register QueueClient's MessageHandler and receive messages in a loop
         RegisterOnMessageHandlerAndReceiveMessages();
 
         Console.ReadKey();