The simplest way, is to check if you've reached the bottom and to trigger then a click-event on your "load more"-button.
$(window).on('scroll', function(){
if( $(window).scrollTop() > $(document).height() - $(window).height() ) {
$("#load-more").click();
}
}).scroll();
The script above is just an example, don't use it in your production environment.
update
...and the better way is to call the function instead of trigger an event which calls the function.
update2
...and the best way: let the user decide what is to do if he do (in this case he scrolls down to reach the end of your page, not to reach the next page) ;)
