//鼠标滑过切换
function $$(id)
{
	document.getElementById(id);	
}
function xovertab(obj, id)
{
	//先把按钮样式替换
	if(id == 1)
	{
			document.getElementById("xnodeshow2").style.display = "none";
			document.getElementById("xntab2").className = "xnode2";
			document.getElementById("xnodeshow1").style.display = "block";
			document.getElementById("xntab1").className = "xnode1";
	}
	else
	{
			document.getElementById("xnodeshow1").style.display = "none";
			document.getElementById("xntab1").className = "xnode2";
			document.getElementById("xnodeshow2").style.display = "block";
			document.getElementById("xntab2").className = "xnode1";
	}
}