function qiehuan(num,length){
	 for(var id = 0;id<=length;id++)
		   {
		     if(id==num)
			{
				document.getElementById("qh_con"+id).style.display="block";
				document.getElementById("mynav"+id).className="timu_on";
				
			}
			else
	       {
				document.getElementById("qh_con"+id).style.display="none";
				document.getElementById("mynav"+id).className="timu_off";
			}
		}
	}
	
	
	
	function menuClass(num,length){
	 for(var id = 0;id<=length;id++)
		   {
		     if(id==num)
			{
				document.getElementById("menu_mynav"+id).className="menu_on";
				
			}
			else
	       {
				document.getElementById("menu_mynav"+id).className="menu_off";
			}
		}
	}
	
	
		function aboutClass(num,length){
	 for(var id = 0;id<=length;id++)
		   {
		     if(id==num)
			{
				document.getElementById("about_mynav"+id).className="about_on";
				
			}
			else
	       {
				document.getElementById("about_mynav"+id).className="about_off";
			}
		}
	}
	
	
	
	
	
	
	
	function startTime()
{
var today=new Date()
  var date = today.getDate();//查询当月日期
  var day = today.getDay();//查询当前星期几
  var month = today.getMonth()+1;//查询月份
  var year = today.getFullYear();//查询年份     

var h=today.getHours()
var m=today.getMinutes()
var s=today.getSeconds()
// add a zero in front of numbers<10
month = checkTime(month)
m=checkTime(m)
s=checkTime(s)
document.getElementById('txt').innerHTML=year+"-"+month+"-"+date+" "+h+":"+m+":"+s
t=setTimeout('startTime()',500)
}

function checkTime(i)
{
if (i<10) 
  {i="0" + i}
  return i
}