JS倒计时使用setInterval调用对象自身方法报 Maximum call stack si

使用JavaScript写的倒计时，使用setInterval调用对象自身方法报 Maximum call stack size exceeded问题 Javascript代码收藏代码

<!doctype html>  
<html>  
    <head>  
        <meta charset='utf-8'/>  
        <title>Title</title>  
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>  
    </head>  
    <body>  
        <div id='m1'><span><b>0</b><b>0</b></span> <span><b>0</b><b>0</b></span> <span><b>0</b><b>0</b></span></div>  
        <div id='m2'><span><b>0</b><b>0</b></span> <span><b>0</b><b>0</b></span> <span><b>0</b><b>0</b></span></div>  
        <script>  
            function CounterDown(id,endtime){  
                this.id=id;  
                this.endtime=new Date(endtime).getTime();  
                this._countTime();  
            }  
            CounterDown.prototype={  
                _countTime:function(){  
                    var timmer;  
                    var now =new Date().getTime();   
                    now = now+1000;  
                    var teamTimeId = this.id,  
                        endtime  = this.endtime,  
                        lasttime = (parseInt(endtime)-parseInt(now)) / 1000,  
                        days     =  Math.floor(lasttime  / (24 * 3600)),  
                        lastSec  = (lasttime - days * 24 * 3600),  
                        hours    = Math.floor(lastSec/3600),  
                        minutes  = Math.floor((lastSec - hours * 3600)/60),  
                        seconds  = Math.floor(lastSec - (hours * 3600) - (minutes * 60));  
                      
                    if(lasttime <= 0){  
                        clearInterval(timmer);  
                        $('#'+teamTimeId).html("<span><b>0</b><b>0</b></span>天<span><b>0</b><b>0</b></span>时<span><b>0</b><b>0</b></span>分<span><b>0</b><b>0</b></span>秒");  
                    }else{  
                        day_0=parseInt(days/10);  
                        day_1=parseInt(days%10);  
                        hours_0=parseInt(hours/10);  
                        hours_1=parseInt(hours%10);  
                        minutes_0=parseInt(minutes/10);  
                        minutes_1=parseInt(minutes%10);  
                          
                        seconds_0=parseInt(seconds/10);  
                        seconds_1=parseInt(seconds%10);  
                          
                        var timerhtml = "";  
                        timerhtml += "<span><b>" + day_0+"</b><b>"+day_1 + "</b></span>天";  
                        timerhtml += "<span><b>" + hours_0+"</b><b>"+hours_1 + "</b></span>时";  
                        timerhtml += "<span><b>" + minutes_0+"</b><b>"+minutes_1 + "</b></span>分";  
                        timerhtml += "<span><b>" + seconds_0+"</b><b>"+seconds_1 + "</b></span>秒";  
                        $('#'+teamTimeId).html(timerhtml);  
                    }  
                    timmer=setInterval(this._countTime,1000);  
                }  
            };  
            new CounterDown('m1',"2014/01/01 10:10:10");      
        </script>  
    </body>  
</html>

在浏览器控制台报如下错误：

请JavaScript高手看看是怎么回事，要怎么解决才好，谢谢！

<!doctype html> <html> <head> <meta charset='utf-8'/> <title>Title</title> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script> </head> <body> <div id='m1'>00 00 00</div> <div id='m2'>00 00 00</div> <script> function CounterDown(id,endtime){ this.id=id; this.endtime=new Date(endtime).getTime(); this._countTime(); } CounterDown.prototype={ _countTime:function(){ var timmer; var now =new Date().getTime(); // now = now+1000; var teamTimeId = this.id, endtime = this.endtime, lasttime = (parseInt(endtime)-parseInt(now)) / 1000, days = Math.floor(lasttime / (24 * 3600)), lastSec = (lasttime - days * 24 * 3600), hours = Math.floor(lastSec/3600), minutes = Math.floor((lastSec - hours * 3600)/60), seconds = Math.floor(lastSec - (hours * 3600) - (minutes * 60)); if(lasttime <= 0){ clearTimeout(timmer); $('#'+teamTimeId).html("00天00时00分00秒"); }else{ day_0=parseInt(days/10); day_1=parseInt(days%10); hours_0=parseInt(hours/10); hours_1=parseInt(hours%10); minutes_0=parseInt(minutes/10); minutes_1=parseInt(minutes%10); seconds_0=parseInt(seconds/10); seconds_1=parseInt(seconds%10); var timerhtml = ""; timerhtml += "" + day_0+""+day_1 + "天"; timerhtml += "" + hours_0+""+hours_1 + "时"; timerhtml += "" + minutes_0+""+minutes_1 + "分"; timerhtml += "" + seconds_0+""+seconds_1 + "秒"; $('#'+teamTimeId).html(timerhtml); } var that = this; var timmer = setTimeout(function() { that._countTime(); }, 500); } }; new CounterDown('m1',"2014/01/01 10:10:10"); </script> </body> </html>