* @param params
	 * @return
	 */
	public static JComboBox combobox(String placeHolder, Object... params) {
		JComboBox cb = new JComboBox();
		
		cb.addItem(placeHolder);
		for (int i = 0; i < params.length; i+=2) {
			cb.addItem(params[i]);
			
		}
		final Map<String, P0> map = Cols.map(params);
		SwingUtil.onChange(cb, new F1<String,Boolean>() {public Boolean e(String label) {
			map.get(label).e();
			return true;
		}});
		return cb;
	}