按钮：点击发送短信按钮60秒内不能再次点击的功能

<script>
    var btn = document.querySelector(‘button‘);
    var time = 60;   // 定义剩下的秒数
    btn.addEventListener(‘click‘, function() {
        btn.disabled = true;
        var timer = setInterval(function() {
            if (time == 0) {
                // 清除定时器和复原按钮
                clearInterval(timer);
                btn.disabled = false;
                btn.innerHTML = ‘发送‘;
                time = 60;   // 剩余时间需要从新开始
            }
            btn.innerHTML = ‘还剩下‘ + time + ‘秒‘;
            time--;
        }, 1000);
    });
</script>