使用js操作css实现js改变背景图片示例

ar imgArr=["//www.VeVB.COm/logo_cn.png",
"//www.VeVB.COm/baidu_sylogo1.gif",
"//www.VeVB.COm/news/uploadImg/20120111/20120111081906_79.jpg",
 "//www.VeVB.COm/news/uploadImg/20120111/20120111081906_76.jpg"];

var index =parseInt(Math.random()*(imgArr.length-1));

var currentImage=imgArr[index];

document.getElementById("BackgroundArea").style.backgroundImage="url("+currentImage+")";

<div id="BackgroundArea">
</div>