<script type="text/javascript">
        var i = 1; var n;
        function showImg() {

            if (document.getElementById('img').getAttribute("src") == "images/1.jpg") {
                document.getElementById('img').setAttribute("src","images/2.jpg");
            }
            else {
                 document.getElementById('img').setAttribute("src","images/1.jpg");
            }
        }

        function showImg1() {
            document.getElementById('img').setAttribute("src", "images/" + i + ".jpg"); i++;
            if (i > 10)
            {
                i = 1;
            }
        }


        function show() {
          n=setInterval(showImg1, 500);
        }

        function show1() {
            clearInterval(n);
        }
    </script>

</head>
<body>
    <img id="img" alt="" src="images/1.jpg" width="200" height="200" />
    <input id="Button1" type="button" value="换图片" onclick="showImg()" />
    <input id="Button2" type="button" value="切图" onclick="showImg1()" />
    <input id="Button3" type="button" value="轮换" onclick="show()" />
        <input id="Button4" type="button" value="停止轮换" onclick="show1()" />

</body>
</html>