如何动态更改startAt值

Question

$('.memberDesc').click(function(){

    var memberid = $(this).attr('rel').valueOf();
    var memberidNo = parseInt(memberid);
      $('.popupBoxFlexslider').flexslider({
        animation: "slide",
        slideshow:false,
        directionNav:true,
        controlNav: false,
        animationLoop:false,
        startAt: memberidNo,
        start: function(slider){
            startAt:memberidNo
        }   
      });
});

即使使用startAt值的变化，flexslider也没有显示特定的li ...我认为一旦flexslider初始化，startAt值就不会改变。你可以帮助我重新初始化它或动态地改变startAt值