//标签框，当鼠标滑到上面时会更换下面的内容
function changebox(title, panel1, panel2, panel3){	
	var node = title.nextSibling;
	while(node){
		node.className = "";				
		node = node.nextSibling;				
	}
	node = title.previousSibling;
	while(node){
		node.className = "";
		node = node.previousSibling;
	}			
	title.className = "active";
	
	document.getElementById(panel1).style.display = "block";
	document.getElementById(panel2).style.display = "none";
	document.getElementById(panel3).style.display = "none";			
}