最终效果
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>倒计时自动获取验证码</title>
</head>
<body>
验证码：<input id="show" type="text"/>
<input id="get_pass" type="button" value="获取验证码"/>
<!-- <span id="spanMa">等待显示</span><br/> -->
</body>
<script type="text/javascript">
window.onload=function(){
$("#get_pass").onclick=function(){
var num=10;
var timer=setInterval(function(){
$("#get_pass").value=num+"秒";
num=num-1;
if(num<=0){
num=10;
showMa();
clearInterval(timer);
$("#get_pass").value="获取验证码";
}
},1000);
$("#show").value="";
}
}
function showMa(){
var str="";
for(var i=0;i<6;i++){
str+=parseInt(Math.random()*10);
}
// $("#spanMa").innerHTML=str;
$("#show").value=str;
}
function $(str){//#box .cls p
if(str.charAt(0)=="#"){
return document.getElementById(str.substring(1));
}else if(str.charAt(0)=="."){
return document.getElementsByClassName(str.substring(1));
}else{
return document.getElementsByTagName(str);
}
}
</script>
