图片轮播

window.setInterval("Huan()",4000);

var n = document.getElementsByTagName("img").length-1;
var d =0;

function Huan()
{

var attr = document.getElementsByTagName("img");


d++;


if(d>n)
{
d = 0;
}


for(var i=0;i<=n;i++)
{
attr[i].style.display = "none";
}

attr[d].style.display = "block";
}