var countdown=60;
function settime(obj) {
if (countdown == 0) {
obj.removeAttribute("disabled");
obj.value="免費(fèi)獲取驗(yàn)證碼";
countdown = 60;
return;
} else {
obj.setAttribute("disabled", true);
obj.value="重新發(fā)送(" + countdown + ")";
countdown--;
}
setTimeout(function() {
settime(obj)
},1000)
}
<input type="button" id="btn" value="免費(fèi)獲取驗(yàn)證碼" onclick="settime(this)" />
注意:有時(shí)候會(huì)失效汰具,在input里加上name即可