短信发送验证码功能

注意，a标签没有disabled属性，所以建议使用button

var count = 0
 send_count_down: function () {
            var code = document.getElementById('sendCode')
            if (count == 0) {
                code.style.color = '#FEC901';
                code.removeAttribute('disabled')
                code.innerHTML = "获取验证码";
                count = 60;
                return;
            } else {
                code.style.color = '#A9A9A9'
                code.setAttribute('disabled', true)
                code.innerHTML = "重新发送(" + count + ")";
                count--;
            }
            setTimeout(function () {
                login.send_count_down()
            }, 1000)
        },