var curIndex = 0;
var arr = new Array();
arr[0] = "top1.gif";
arr[1] = "top2.gif";
arr[2] = "top3.gif";
setInterval(changeImg, 3000);
function changeImg() {
var obj = document.getElementById("top_img");
if (curIndex == arr.length - 1) {
curIndex = 0;
}
else {
curIndex += 1;
}
obj.src = "/images_NewSite/" + arr[curIndex];
}