When registering, you need to send an email to verify the account activation. In order to avoid repeated sending of the email, you can set the button to wait for a while after clicking send before you can continue to click it. Here is a simple example:
<<a href="http://www.php1.cn/">html</a>>
<head>
<title>点击获取验证码按钮后按钮变灰，倒计时一段时间后又可重复点击</title>
</head>
<body>
<input type="button" id="btn" value="免费获取验证码" />
<script type="text/javascript">
var wait=60;
function time(o) {
if (wait == 0) {
o.removeAttribute("disabled");
o.value="免费获取验证码";
wait = 60;
} else {
o.setAttribute("disabled", true);
o.value=wait+"秒后可以重新发送";
wait--;
setTimeout(function() {
time(o)
},
1000)
}
}
document.getElementById("btn").onclick=function(){time(this);}
</script>
</body>
</html>
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
