l两张图片轮播

在head里面加

<script language="javascript">
function scroll(spanlevel) {
 if (spanlevel.style.zIndex == 0) {
 spanlevel.style.zIndex = 2;

 } else {
 spanlevel.style.zIndex = 0;
 }
 }
 setInterval("scroll(span2)", 2000);

</script>

在body里面

<div id="span1" style="position: absolute; margin-top: 10px; float: left;
  z-index: 1;">
 <img alt="" src="11.jpg" style="width:1266px" />
</div>
<div id="span2" style="position: absolute; margin-top: 10px; float: left;
  z-index: 0;">
 <img alt="" src="222.jpeg"  style="width:1266px"/>
</div>