js设置随机切换背景图片的简单实例

<script> var imgs =["http://images.cnblogs.com/cnblogs_com/xiaobo-Linux/1112236/o_2.jpg",       "http://images.cnblogs.com/cnblogs_com/xiaobo-Linux/1112236/o_default.png",       "http://images.cnblogs.com/cnblogs_com/xiaobo-Linux/1112236/o_3.jpg",       "http://images.cnblogs.com/cnblogs_com/xiaobo-Linux/1112236/o_1.jpg",       "http://images.cnblogs.com/cnblogs_com/xiaobo-Linux/1112236/o_4.jpg",       "http://images.cnblogs.com/cnblogs_com/xiaobo-Linux/1112236/o_5.jpg",       "http://images.cnblogs.com/cnblogs_com/xiaobo-Linux/1112236/o_6.jpg",       "http://images.cnblogs.com/cnblogs_com/xiaobo-Linux/1112236/o_default-2.jpg",       ];   var index=Math.floor(Math.random()*8);var img = imgs[index];    function time(){               document.body.style.backgroundImage="url("+img+")";            }   document.body.onload = function(){ time();}</script>