发送短信后倒计时效果

function clickButton(obj){
    var obj = $(obj);
    obj.attr("disabled","disabled");
    var time = 180;
//设置倒计时以毫秒进行计算，1000毫秒后减1
 var set=setInterval(function(){
    obj.val(--time);
    }, 1000);
    setTimeout(function(){
    obj.attr("disabled",false).val("获取验证码");
//取消setinterval当180000毫秒以后
 clearInterval(set);
    }, 180000);
}


<div class="col-sm-4">
  <input class="btn btn-sm" id="verify" type="button" onclick="clickButton(this);" value="获取短信验证码" />
</div>