Selector on Browser, how to do?

Hi all,
I try to filter a specific message of a queue I want to delete (I have the message ID from a call before).
How to set the selector?
this is my code and I tried a lot of variations on the selector
for example
mi = '485'
mi = 485
JMSMessageID = 485
JMSMessageID = '485'
etc.
when I browse via the console and select a message the only parameter is the message ID so what is the actual call (with java) to delete that message?

below my java code:

 public Boolean DeleteMessageWithBrowser(String destination, int waitTimeout, String messageId) {
        try {
            session = JCSMPFactory.onlyInstance().createSession(properties);
            session.connect();

            queue = JCSMPFactory.onlyInstance().createQueue(destination);
            BrowserProperties br_prop = new BrowserProperties();
            br_prop.setEndpoint(queue);
            br_prop.setTransportWindowSize(1);
            br_prop.setSelector("mi = '"+messageId+"'"); 
            br_prop.setWaitTimeout(waitTimeout);
            Browser myBrowser = session.createBrowser(br_prop); 
            myBrowser.remove(myBrowser.getNext());
            myBrowser.close();
         }
         catch (JCSMPException e) {
             _logNode.debug("Error when getting message, session close. Error: "+e.getMessage());
             if( session != null && !session.isClosed() ) {
                 session.closeSession();
             }
        }   
        finally {
         if( session != null && !session.isClosed() ) {
                _logNode.debug("Message browsed. Exiting.");
                session.closeSession();
         }
     }
        return true;
    }

thx!