<script language =javascript >

var curIndex=0;

//时间间隔 单位毫秒

var timeInterval=2000;

var arr=new Array();

arr[0]="images/1.jpg";

 arr[1]="images/2.jpg";

arr[2]="images/3.jpg";

arr[3]="images/4.jpg";

setInterval(changeImg,timeInterval);

function changeImg()

{

    var obj=document.getElementById("obj");

    if (curIndex==arr.length-1) 

    {

        curIndex=0;

    }

    else

    {

       curIndex+=1;

    }

    obj.src=arr[curIndex];

}

</script>

<center>

<img id=obj src ="images/1.jpg" height="450" width="1920" border =0 title="默认图片"/>

</center>