JS计算时间天数

<script type="text/javascript">
  function  btnCount_Click(){  
	 var myDate = new Date();
		this.myHour = myDate.getHours();
		this.myMinute = myDate.getMinutes();
		if(myMinute<10){
			myMinute="0"+myMinute;
		}
		this.mySeconds = myDate.getSeconds(); 
		if(mySeconds<10){
			mySeconds="0"+mySeconds;
		}
		this.myWeek =  myDate.getDay();
		this.myYear =  myDate.getFullYear() +'-';
		this.myMonth = myDate.getMonth()+1+'-';
		this.myDatee = myDate.getDate(); 
		var time=myYear+myMonth+myDatee+" "+myHour+":"+myMinute+":"+mySeconds;
		  s1  =  "2010-12-27"  ;
       s2  =  myYear+myMonth+myDatee ;
		document.getElementById('span_time').value=time+" | "+DateDiff(s1,s2)+"天";
		   setTimeout('btnCount_Click()',1000);
       //alert("第一个日期；"+s1+"\n第二个日期："+s2+"\n相差"+DateDiff(s1,s2)+"天")  ;
   }  
 
   //计算天数差的函数，通用  
   function  DateDiff(sDate1,  sDate2){    //sDate1和sDate2是2006-12-18格式  
       var  aDate,  oDate1,  oDate2,  iDays  
       aDate  =  sDate1.split("-")  
       oDate1  =  new  Date(aDate[1]  +  '-'  +  aDate[2]  +  '-'  +  aDate[0])    //转换为12-18-2006格式  
       aDate  =  sDate2.split("-")  
       oDate2  =  new  Date(aDate[1]  +  '-'  +  aDate[2]  +  '-'  +  aDate[0])  
       iDays  =  parseInt(Math.abs(oDate1  -  oDate2)  /  1000  /  60  /  60  /24)    //把相差的毫秒数转换为天数  
       return  iDays  
   }    

</script>
<input id="span_time" type="text" style="width:200px"/>
<script>
btnCount_Click();
</script>