public String getRoutAtrr(){
		int i;
		int val;
		String key;
		Map.Entry<String, Integer> me;
		
		if(routAtrr != null)
			return routAtrr;
		
		while((me = attr.pollFirstEntry())!= null){
			key = me.getKey();
			val = me.getValue();
			for(i = 0; i < attrCdt.size(); i++){
				if(val >= attrCdtVal.get(i))
					break;
			}
			attrCdt.add(i, key);
			attrCdtVal.add(i, val);
		}
			
		for(String s : attrCdt){
			if(isValidRoutAttr(s)){
				routAtrr = s;
				break;
			}
		}

		if(routAtrr == null){
			if(attrCdt.size() != 0)
				routAtrr = attrCdt.getFirst();
			else
				routAtrr = "No attribute Candidates!";
		}
		attr = null;	// free attr TreeMap
		return routAtrr;
	}