public void inc(String s, int cnt){
		if(cnt <= 0) return;
		s = s.toLowerCase();
		if(attr.containsKey(s)){
			int val = attr.remove(s);
			attr.put(s, val + cnt);
		}
		else{
			attr.put(s, cnt);
		}
		incNumTxn(cnt);		// TODO cancel this when Arpit finished
	}