Windows Phone 7 client server implementation - windows-phone-7

Question

I'm trying to create an application for windows phone 7 which acts as a client and which sends requests to a server which is written in Java. The client supposed to send a request, and wait for an answer from the server.
My problem is that I can't seem to communicate with the server properly. When I tried testing it in a simple .NET C# program and used blocking calls such as socket.send() and socket.receive() it works but the Windows Phone application doesn't have blocking calls.
This is what the server (Java) does once it detects a connection:
BufferedReader reader = new BufferedReader(new InputStreamReader(clientSocket.getInputStream(), "UTF-8"));
String message = reader.readLine();
PrintWriter writer = new PrintWriter(new OutputStreamWriter(clientSocket.getOutputStream(), "UTF-8"));
writer.println("hiBack");
writer.close();
and this is how the client(C#) is implemented:
public void sendRequest()
{
socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
var connectionOperation = new SocketAsyncEventArgs { RemoteEndPoint = new DnsEndPoint(server, serverPort) };
connectionOperation.Completed += new EventHandler<SocketAsyncEventArgs>(onConnectCompleted);
socket.ConnectAsync(connectionOperation);
}
private void onConnectCompleted(object sender, SocketAsyncEventArgs e)
{
if (e.SocketError != SocketError.Success)
{
System.Console.WriteLine("Error! " + e.SocketError);
return;
}
var sendListener = new SocketAsyncEventArgs();
string msg = "hi";
var buffer = new System.Text.UTF8Encoding().GetBytes(msg + Environment.NewLine);
sendListener.SetBuffer(buffer, 0, buffer.Length);
sendListener = new SocketAsyncEventArgs { RemoteEndPoint = new DnsEndPoint(server, serverPort) };
sendListener.Completed += new EventHandler<SocketAsyncEventArgs>(onSendCompleted);
socket.SendToAsync(sendListener);
}
private void onSendCompleted(object sender, SocketAsyncEventArgs e)
{
socket.ReceiveAsync(e);
}
I've got a problem with the line: socket.SendToAsync(sendListener); on the C# side which end the program without doing anything (exit with return code 0).
the Java server starts it's work instantly when it detects the connection so it might also cause a problem?
What can I do to make the communication work?