jquery - How do I stop the duration of the scrollTop -

the directive have works enough far, not every page has same height want stop duration when @ bottom.

this code of directive:

function (scope, elem, attrs) {         $(document).on('contentchanged', '#maintext',  function () {             $("html, body").animate({                 scrolltop: 0             }, 0),             $("html, body").animate({                 scrolltop: $(window).height()             }, 4000);         });     } 

so example @ first page view @ bottom can't go lower , when go next page bit lower continuous scrolling down.

my question how can stop scrolling ?

.animate( properties [, duration] [, easing] [, complete] ) 

so this:

.animate(      {scrolltop:'300px'},     300,     swing,     function(){         alert(animation complete! - custom code here!);         }      ) 

here jquery .animate function api page: http://api.jquery.com/animate/