on mouse smooth scroll

smooth-scroll-mouse.js

<script>
//final script scroll 
 if (window.addEventListener) window.addEventListener('DOMMouseScroll', wheel, false);
window.onmousewheel = document.onmousewheel = wheel;

var time = 1300;
var distance = 270;

function wheel(event) {
    if (event.wheelDelta) delta = event.wheelDelta / 120;
    else if (event.detail) delta = -event.detail / 3;

    handle();
    if (event.preventDefault) event.preventDefault();
    event.returnValue = false;
}

function handle() {

    $('html, body').stop().animate({
        scrollTop: $(window).scrollTop() - (distance * delta)
    }, time);
}


$(document).keydown(function (e) {

    switch (e.which) {
        //up
        case 38:
            $('html, body').stop().animate({
                scrollTop: $(window).scrollTop() - distance
            }, time);
            break;

            //down
        case 40:
            $('html, body').stop().animate({
                scrollTop: $(window).scrollTop() + distance
            }, time);
            break;
    }
});

</script>