js怎样实现横向滚动与浮动导航

#demo {
 background: #FFF;
 overflow: hidden;
 border: 1px dashed #CCC;
 width: 1170px;border: 1px solid red;
 margin-left: 10px;
}#demo img {border: 3px solid #F2F2F2;
}#indemo {float: left;width: 800%;
}#demo1 {float: left;
}#demo2 {float: left;
}

 <p id="demo" ><p id="indemo"><p id="demo1"><a href="#"><img src="../Images/jiameng/1.png" border="0" /></a><a href="#"><img src="../Images/jiameng/2.png" border="0" /></a><a href="#"><img src="../Images/jiameng/3.png" border="0" /></a><a href="#"><img src="../Images/jiameng/4.png" border="0" /></a><a href="#"><img src="../Images/jiameng/5.png" border="0" /></a><a href="#"><img src="../Images/jiameng/6.png" border="0" /></a><a href="#"><img src="../Images/jiameng/7.png" border="0" /></a><a href="#"><img src="../Images/jiameng/8.png" border="0" /></a></p><p id="demo2"></p>

<script> var speed = 10; var tab = document.getElementById("demo"); var tab1 = document.getElementById("demo1"); var tab2 = document.getElementById("demo2");
 tab2.innerHTML = tab1.innerHTML; function Marquee() { if (tab2.offsetWidth - tab.scrollLeft <= 0) {
 tab.scrollLeft -= tab1.offsetWidth;
 
 } else {
 tab.scrollLeft += 2;
 
 }
 } var MyMar = setInterval(Marquee, speed);
 tab.onmouseover = function () { clearInterval(MyMar); };
 tab.onmouseout = function () { MyMar = setInterval(Marquee, speed); };</script>

<script type="text/javascript" src="http://misc.jjcdn.com/resource/js/waypoints.js"></script> 
<script type="text/javascript"> 
//浮动导航 waypoints.js $('#main-nav-holder').waypoint(function (event, direction) { 
$(this).parent().toggleClass('sticky', direction === "down"); 
event.stopPropagation(); 
}); 
</script>