var _countdown={};
_countdown.now=1215182375;
_countdown.end=1221840000;
_countdown.seconds=_countdown.end-_countdown.now;
_countdown.element=document.getElementById("countdown");
function countdown(){
	var seconds=--_countdown.seconds;
	var second=seconds%60;
	var minutes=Math.floor(seconds/60);
	var minute=minutes%60;
	var hours=Math.floor(minutes/60);
	var hour=hours%24;
	var day=Math.floor(hours/24);
	_countdown.element.innerHTML=day+"天"+hour+"时"+minute+"分"+second+"秒";
}
setInterval("countdown()",1000);