javascript check if user has scrolled to the botton of the page 
 Edit
                    
                    
                    display a console message "reached bottom" when the user has the window to the bottom of the page. please find the code below.
Javascript Code
$(window).scroll(function () {
        if ($(window).scrollTop()   $(window).height() > $(document).height() - 100) {
            console.log("reached bottom");
        }
    });