입력한 날짜에 년수 더한 날짜 출력하기

var today = new Date();
var dateString = '2014-12-14';
 var dateArray = dateString.split("-");
 var dateObj = new Date(dateArray[0], Number(dateArray[1])-1, dateArray[2]);
  dateObj.setFullYear(dateObj.getFullYear() + 2 ));

 yy = dateObj.getFullYear();
  mm = dateObj.getMonth() + 1; mm = (mm < 10) ? '0' + mm : mm;
 dd = dateObj.getDate(); dd = (dd < 10) ? '0' + dd : dd;

$('#exchngTrgetDt').val(yy + '-' +  mm  + '-' + dd);