function init(){
    new SmoothScroll(document,120,12)
}

function SmoothScroll(target, speed, smooth) {
    if (target === document)
        target = (document.scrollingElement 
              || document.documentElement 
              || document.body.parentNode 
              || document.body) // cross browser support for document scrolling
      
    var moving = false
    var pos = target.scrollTop
  var frame = target === document.body 
              && document.documentElement 
              ? document.documentElement 
              : target // safari is the new IE
  
    target.addEventListener('mousewheel', scrolled, { passive: false })
    target.addEventListener('DOMMouseScroll', scrolled, { passive: false })

    function scrolled(e) {
        e.preventDefault(); // disable default scrolling

        var delta = normalizeWheelDelta(e)

        pos += -delta * speed
        pos = Math.max(0, Math.min(pos, target.scrollHeight - frame.clientHeight)) // limit scrolling

        if (!moving) update()
    }

    function normalizeWheelDelta(e){
        if(e.detail){
            if(e.wheelDelta)
                return e.wheelDelta/e.detail/40 * (e.detail>0 ? 1 : -1) // Opera
            else
                return -e.detail/3 // Firefox
        }else
            return e.wheelDelta/120 // IE,Safari,Chrome
    }

    function update() {
        moving = true
    
        var delta = (pos - target.scrollTop) / smooth
    
        target.scrollTop += delta
    
        if (Math.abs(delta) > 0.5)
            requestFrame(update)
        else
            moving = false
    }

    var requestFrame = function() { // requestAnimationFrame cross browser
        return (
            window.requestAnimationFrame ||
            window.webkitRequestAnimationFrame ||
            window.mozRequestAnimationFrame ||
            window.oRequestAnimationFrame ||
            window.msRequestAnimationFrame ||
            function(func) {
                window.setTimeout(func, 1000 / 50);
            }
        );
    }()
}