javascript is scroll bottom function

scroll.js

function isBottom(){
    var windowHeight = window.innerHeight
        || document.documentElement.clientHeight
        || document.body.clientHeight;
    var scrollTop = $(window).scrollTop();
    var totalHeight = $(document).height();
    var percent = (windowHeight + scrollTop)/totalHeight;
    if(percent === 1){
        return true;
    }else{
        return false;
    }
}