6.5轮播图

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
</head>

<body>
<script type="text/javascript">
	var b = 0;
	function demo(){
		var a = document.getElementById("s");
/*		
		if(a.src == "../image/1.png"){
			a.src="../image/2.png"
		}else if(a.src == "../image/2.png"){
			a.src="../image/3.png"
		}else if(a.src == "../image/3.png"){
			a.src="../image/1.png"
		}
*/
		var c = b%3+1;
		a.src = "../image/"+c+".png";
		b++;		
	}
	window.setInterval("demo()",1000);
</script>
<img src="../image/1.png" id="s">
</body>
</html>