js實現頁面的秒數倒計時

<button name="vcode_mail" class="btn btn-default" type="button" id="vcode_mail-btn" onclick="vcode_mail_post(this)">免費獲取驗證碼</button>

 

 

js

    //發送驗證碼
    function vcode_mail_post(obj){
        var seconds =121;

        //獲取郵箱
        var email = $("input[name='email']").val();
        //異步變同步
        /*$.ajaxSettings.async = false;*/
        //發送請求
        $.post("{:url('index/user/vcode_mail_post')}",{email:email,type:1},function(data){

            var message = data.message;
            if(data.ok == '1'){
                alert(message);
                //倒計時
                daojishi(seconds,obj);    
            }else{
                alert(message);

            }
        },'json');
        /*$.ajaxSettings.async = true;*/
    }

    //倒計時
    function daojishi(seconds,obj){

        if (seconds > 1){

                seconds--;

                $(obj).text(seconds+"秒后可重新獲取 ").attr("disabled", true);//禁用按鈕

                // 定時1秒調用一次

                setTimeout(function(){

                    daojishi(seconds,obj);

                },1000);

            }else{

                $(obj).text("重新獲取驗證碼").attr("disabled", false);//啟用按鈕

            }        
    }