function countDown(){
var step = 59;
$("#sendCode").html("重新发送60");
var count_Down = setInterval(function(){
$("#sendCode").attr("disabled", true);//设置disabled属性
$("#sendCode").html("重新发送"+step);
step-=1;
if(step <= 0){
$("#sendCode").removeAttr("disabled"); //移除disabled属性
$("#sendCode").html("获取验证码");
clearInterval(count_Down);//清除setInterval
}
},1000);
}