//展开/隐藏 节点的子节点。根据图标判断，若当前为展开状态，则使其变为隐藏状态。反之亦然
function TurnIt(path)
{
	var imageEx = "add.gif";
	var imageSh = "sub.gif";
	var imgPath = "Img" + path;
	var trPath = "tr" + path;

	var strImgSrc = new String(document.all(imgPath).src);
	var level = document.all(trPath).level;
	
	//若当前为加号，则展开下级：
	if (strImgSrc.indexOf(imageEx) >= 0)
	{
		document.all(imgPath).src = "../Images/Category/" + imageSh;
		for(var v in document.all)
		{
			if (document.all(v) != null)
				if (v.indexOf(trPath) == 0 && v != trPath)
					if(document.all(v).driver == level)
					{
						document.all(v).style.display = "";
						document.all(v).driver = null
					}
		}
	}
	//若当前为减号，则隐藏下级：
	else if (strImgSrc.indexOf(imageSh) >= 0)
	{
		document.all(imgPath).src = "../Images/Category/" + imageEx;
		for(var v in document.all)
		{
			if (document.all(v) != null)
				if (v.indexOf(trPath) == 0 && v != trPath)
				{
					document.all(v).style.display = "none";
					if(document.all(v).driver == null)
						document.all(v).driver = level;
				}
		}
	}
}