How to keep while loop adding minutes

function() {

           var toTime = new Date(result2);

           while (true) {

               var toTime30 = new Date(toTime.getTime() + toTime.getTimezoneOffset() *30 * 1000);
               var toTime60 = new Date(toTime30.getTime() + 30 * 60 * 1000);

               var addMin = toTime30 + "" + toTime60;


                   alert(addMin);
                   break;

           }