shyamseshadri/angularjs-up-and-running — pull request #12 by icese7en (2014-11-20 14:07:50+00:00)
Title: Offer an solution for the 1.3.x version

People who use angular.js 1.3.x cannot run this code directly because the ng-true-value of 1.3.x must be a constant string. And there need a single quote to wrap the value we want to use like 'YES' and 'NO' in this case