function nav_init(){
	for (i=0; i<=7; i++)//初始化每个栏目中间那张图片
	{
		if (menu_id==i)
		{
			document.getElementById("Image"+i).src = "images/bt_nav0"+ (i+1) +".jpg";
		}
		else
		{
			document.getElementById("Image"+i).src = "images/bt_nav"+ (i+1) +".jpg";
		}
	}
	for (i=1; i<=7; i++)//初始化中间的小图片
	{
		if (menu_id==i)
		{
			document.getElementById("nav"+i).src = "images/point_nav2.jpg";
		}
		else if(menu_id==(i-1))
		{
			document.getElementById("nav"+i).src = "images/point_nav3.jpg";
		}
		else
		{
			document.getElementById("nav"+i).src = "images/point_nav1.jpg";
		}
	}
}
function nav_over(id)
{
	for (i=1; i<=7; i++)
	{
		document.getElementById("nav"+i).src	= "images/point_nav1.jpg";
	}

	for (i=0; i<=7; i++)
	{
		document.getElementById("Image"+i).src	= "images/bt_nav"+ (i+1) +".jpg";
	}

	if (id==0)
	{
		document.getElementById("nav1").src		= 'images/point_nav3.jpg';
		document.getElementById("Image0").src	= 'images/bt_nav01.jpg';
	}
	else if (id==7)
	{
		document.getElementById("nav7").src		= 'images/point_nav2.jpg';
		document.getElementById("Image7").src	= 'images/bt_nav08.jpg';
	}
	else
	{
		document.getElementById("nav"+id).src		= 'images/point_nav2.jpg';
		document.getElementById("nav"+(id+1)).src	= 'images/point_nav3.jpg';
		document.getElementById("Image"+id).src		= "images/bt_nav0"+ (id+1) +".jpg";
	}
	return;
}
function nav_out(pName)
{
	var obj = event.toElement;
	while(obj!=null && obj.id!=pName )
	{
		obj = obj.parentElement;
	}
	if (obj==null)
	{
		nav_init();
	}
}