I used moment js for this ... u can get it from here

     /*

     all functions return moment() object.. <br>

     GetNextWeekStart().format('DD/MM/YYYY') to get 24/02/2014

     */



     function GetNextWeekStart() {

            var today = moment();

            //edited part

            var daystoMonday = 0 - (today.isoWeekday() - 1) + 7;       

            var nextMonday = today.subtract('days', daystoMonday);



            return nextMonday;

        }



        function GetNextWeekEnd() {

            var nextMonday = GetNextWeekStart();

            var nextSunday = nextMonday.add('days', 6);



            return nextSunday;

        }



        function GetLastWeekStart() {

            var today = moment();

            var daystoLastMonday = 0 - (1 - today.isoWeekday()) + 7;



            var lastMonday = today.subtract('days', daystoLastMonday);



            return lastMonday;

        }



        function GetLastWeekEnd() {

            var lastMonday = GetLastWeekStart();

            var lastSunday = lastMonday.add('days', 6);



            return lastSunday; 

        }