javascript - scrollTop not working when I reach a certain div -

i trying implement on scroll load.

this code on-scroll

$(window).on("scroll", function(){     if( ($(window).scrolltop()-350) + $(window).height() == $(document).height()){          loaddata();     } }); 

i subtracting 350 scrolltop because want ajax request fire on div comes viewport.

why code not working.

here loaddata function has ajax request.

however, when run code, works:

$(window).on("scroll", function(){     if($(window).scrolltop() + $(window).height() == $(document).height()){          loaddata();     } }); 

but, have go end of page ajax request fire.

why code not working subtract 350 scrolltop??? need fire ajax when reach div, how do that??

there 2 separate issues here; 1 you're testing exact scroll position, other want adding 350px scroll position rather subtracting (so function fire 350px before end of window, rather 350px after end of it.)

try this:

if( $(window).scrolltop() + $(window).height() + 350 >= $(document).height()) {     loaddata(); } 

but remember scroll events fire continuously , want loaddata() fire once! therefore:

var loadeddata = false; $(window).on("scroll", function() {   if (loadeddata) return;   if ($(window).scrolltop() + $(window).height() + 350 >= $(document).height()) {     alert("fire loaddata now");     loadeddata = true;     loaddata();   } }); 

...and have loaddata() function set loadeddata false re-enable scroll trigger, if necessary.

http://plnkr.co/edit/4qeguridrq6nchfvuint