try
{
    MQQueueManager qmgr = new MQQueueManager( "localhost" );
    MQQueue queue = qmgr.AccessQueue( "HELLO.QUEUE",
        MQC.MQOO_OUTPUT +            // open queue for output
        MQC.MQOO_FAIL_IF_QUIESCING   // but not if MQ is stopping
    ); 
    MQMessage msg = new MQMessage();
    msg.WriteString( "Hello World" );
    queue.Put( msg );
    queue.Close();
    qmgr.Disconnect();
}
catch( MQException mqe ) { 
    // ...
}