public String getValue(String className, String tagName)
	{
		if(messages != null) {
			classes = messages.getChildren("class");
			@SuppressWarnings("rawtypes")
			Iterator i = classes.iterator();
			
			while(i.hasNext())	//scan classes to find the good one
		    {
		      Element current = (Element)i.next();
		      if(current.getAttributeValue("name").equals(className)){
		    	  //System.out.printf("Found class <%s>\n",className);
		    	  List tags = current.getChildren("tag");
		    	  Iterator j = tags.iterator();
		    	  while(j.hasNext()) {
		    		  Element curtag = (Element)j.next();
		    		  if(curtag.getAttributeValue("name").equals(tagName)) {
		    			  //System.out.printf("Found tag <%s>\n",curtag.getAttributeValue("name"));
				    	  return curtag.getAttributeValue("msg");
		    		  }
		    	  }
		    	  return null;
		      }
		      
		    }
		}
		return null;	//class not found
	}