JS獲取JSON對象數組某個屬性最大值

            var name_value= [{"name":"閔行區","value":20},{"name":"浦東新區","value":30},{"name":"楊浦區","value":10}]
            var list = new Array();
            for(var i in name_value){
            list.push(name_value[i].value);
            }
            list.sort(function(num1,num2){
            return num1-num2;
            })
            var maxcnt= eval(list[list.length-1]);