<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
<style type="text/css">
#btn {
width: 150px;
height: 40px;
background: green;
font-size: 17px;
}
</style>
<script type="text/javascript" src="js/jquery-1.11.1.min.js"></script>
<script type="text/javascript">
$(function() {
$('#btn').click(function() {
var reg = /^1\d{10}$/;
if ($('#num').val() == "") {
alert('请输入电话好吗？');
} else if (!reg.test($('#num').val())) {
alert('请输入正确的电话好吗？');
} else {
$(this).css('background', 'blue').css('color', 'red');
var i = 5;
var n = setInterval(function() {
var j = i + 's';
$('#btn').val(j);
i--;
if (i < -1) {
clearInterval(n);
$('#btn').val('重新获取验证码!');
}
}, 1000);
}
});
})
</script>
</head>
<body>
<input type="text" autofocus="autofocus" id="num" />
<input type="button" value="获取验证码" id="btn" />
</body>
</html>
