JavaScript根据剩余多少秒实现倒计时

function test(second){                        //传入秒
		var second = second;            //秒
		var minute=0;                    //分钟
		var hour=0;                    //小时
		var day=0;                    //天
		minute = parseInt(second/60); 		//算出一共有多少分钟
		second%=60;							//算出有多少秒
		if(minute>60) { 					//如果分钟大于60，计算出小时和分钟
		    hour = parseInt(minute/60);
		    minute%=60;						//算出有多分钟
		}
		if(hour>24){						//如果小时大于24，计算出天和小时
		    day = parseInt(hour/24);
		    hour%=24;						//算出有多分钟
		}
		second = second>9?second:"0"+second;
		minute = minute>9?minute:"0"+minute;
		hour = hour>9?hour:"0"+hour;
		return day+"天"+hour+"小时"+minute+"分钟"+second+"秒";            //返回剩余天小时分钟秒
	}