利用定时器 ，制作按钮在有效时间内失效的效果
可用作于接收验证码
避免了用户多次连续点击
【效果如下】
<!DOCTYPE html>
<html><head><meta charset="utf-8"><title></title></head><body></body><script type="text/javascript">//创建button按钮var _btn = document.createElement("button");document.body.appendChild(_btn);_btn.innerText = "验证码";_btn.style.width = "100px";_btn.style.height = "50px";_btn.style.fontSize = "20px";//定时器var count = 10;_btn.onclick = function() {var time = setInterval(function() {if (count <= 0) {_btn.disabled=false;count = 10;_btn.innerText = '验证码';clearInterval(time);} else {_btn.innerText = count;count--;_btn.disabled=true;}}, 1000)}// var time = setTimeout('_btn', 1000);// if (count == 0) {// clearInterval(time);// }// _btn.innerText = count;// count--;</script>
</html>
