Animate Not Working on Scrool

Animate Not Working on Scrool

Can you please take a look at this demo and let me know why the second part of targeting the scroll position is not working? what I want to do is targeting scrool postion between 450 to 600 and applying this animation
  1. $(".box-caption").animate({ "top": "600px" },1000);

 to the element

  1. $(function() {
        $( window ).scroll(function(e) {
        var y =   $( window ).scrollTop();
          if (y >200  && y< 400){
           $(".box-caption").animate({ "top": "350px" },1000);
        }
           if (y >450  && y< 600){
           $(".box-caption").animate({ "top": "600px" },1000);
        }
        });
    }); 
as you can see it is working on first animate but not working for second! can you please let me know why this is happening and how I can fix it? thanks