jquery - How to add a callback with scrolltop and animate -

for ie8 use code uses jquery animate banner @ bottom of page when user scrolls 250 or more. problem extremely slow , has huge delay, believe because animate event firing many times, need callback written in .stop(); i'm not sure how/where put this. ideas?

} else { $(window).scroll(function() {   if ($(this).scrolltop() < 250) {      if($("#carriage-promo").not(':animated')){         $("#carriage-promo").animate({            height: 0         },100);       }   } else {      if($("#carriage-promo").not(':animated')){         $("#carriage-promo").animate({            height: '40px'         },100);      }   } }); } 

try this:

$(window).scroll(function() {   if ($(this).scrolltop() < 250) {      if($("#carriage-promo").not(':animated')){         $("#carriage-promo").stop(true,true).animate({            height: 0         },100);       }   } else {      if($("#carriage-promo").not(':animated')){         $("#carriage-promo").stop(true,true).animate({            height: '40px'         },100);      }   } });