<body><imgid="light"src="img/off.jpg"><script>var light = document.getElementById("light");var flag =false;if(flag){
light.src ="img/on.jpg";
flag =false;}else{
light.src ="img/off.jpg";
flag =true;}</script></body>
轮播图案例
<body><imgsrc="../../../../imgs/banner_1.jpg"width="100%"id="img"><script>var number =1;/*修改图片*/functionfun(){
number ++;if(number >3){
number =1;}var img = document.getElementById("img");
img.src ="../../../../imgs/banner_"+ number +".jpg";}setInterval(fun,3000);</script></body>