A Question About MSMQ(Microsoft Message Queue) in .net 2.0

When the code below executes,the btnSendMessage_Click method(Send Message) can complete normally.
But the btnReceiveMessage_Click method blocks at 'queue.Receive();' without any exception.Why can't
receive message?Do I need to configure my OS(Windows XP) yet ?
Any help will be appreciated!

// Send Message
private void btnSendMessage_Click(object sender, System.EventArgs e)
{

       // Open queue
       System.Messaging.MessageQueue queue = 
                    new System.Messaging.MessageQueue(".\\Private$\\MSMQDemo");

       // Create message
       System.Messaging.Message message = new System.Messaging.Message();

       message.Body = txtMessage.Text.Trim();

       message.Formatter = new System.Messaging.XmlMessageFormatter(new Type[] {typeof(string)});

       // Put message into queue
       queue.Send(message);

}

 

// Receive Message
private void btnReceiveMessage_Click(object sender, System.EventArgs e)
{

       // Open queue
       System.Messaging.MessageQueue queue = 
                   new System.Messaging.MessageQueue(".\\Private$\\MSMQDemo");

 
      // Receive message
       System.Messaging.Message message = queue.Receive(); 

       message.Formatter = new System.Messaging.XmlMessageFormatter(new Type[] {typeof(string)});

       txtReceiveMessage.Text = message.Body.ToString();
}