＜html>
＜head>
＜title>＜/title>

＜script language="JavaScript">
＜!--
//请先准备几张JPG图片格式的,名字是demo1.jpg,demo2.jpg,demo3.jpg
if (document.images) {
demo1 = new Image();
demo1.src = "../../images/demo1.jpg";

demo2 = new Image();
demo2.src = "../../images/demo2.jpg";

demo3 = new Image();
demo3.src = "../../images/demo3.jpg";
}

function timeimgs(numb) {
thetimer = setTimeout("imgturn('" +numb+ "')", 1000);
}

function imgturn(numb) {
if (document.images) {

if (numb == "3") {
document["demo"].src = eval("demo3.src");
timeimgs('1');
}

else { document["demo"].src = eval("demo" + numb + ".src");

timeimgs(numb = ++numb);
}
}
}

// -->
＜/script>

＜/head>
＜body onload="timeimgs('2');">

＜img src="../../images/demo1.jpg" name="demo" width="100" height="100" alt="demo">