页面滚动下拉时,元素变为fixed浮动js代码 以视频示例

javascript"><style>video{width:100%;height:auto}.div2,#float1{position:fixed;_position:absolute;top:45px;right:0; z-index:250;}button{float:right;display:block;margin:5px}
</style><section id="about-page"><div id="float1"style="margin:0 auto;display:none"><button onclick="showVideo()">显示视频</button></div> 	<div id="float2"style="margin:0 auto;background:#000;"><video id="myVideo" src="视频地址" controls autoplay></video><button onclick="pauseVideo()">关闭视频</button>
</div> 	   
其它文章内容
</section><script>
//关闭开启视频
function pauseVideo() {var video = document.getElementById("myVideo");video.pause();$('#float2').stop().fadeOut();$('#float1').show();
}
function showVideo() {var video = document.getElementById("myVideo");video.play();$('#float2').show();$('#float1').stop().fadeOut();
}//	 滚动(function(){
var oDiv=document.getElementById("float2");
//alert(document.getElementById("my-left-div").offsetWidth);
var H=0,iE6;
var Y=oDiv;
while(Y){H+=Y.offsetTop;Y=Y.offsetParent};
iE6=window.ActiveXObject&&!window.XMLHttpRequest;
if(!iE6){
window.onscroll=function()
{
var s=document.body.scrollTop||document.documentElement.scrollTop;
if(s>H){oDiv.className="div1 div2";
if(iE6){oDiv.style.top=(s-H)+"px";}}
else{oDiv.className="div1";
}
};
}
})();
</script>