用按钮实现访问兄弟节点?怎样点了按钮不消失?
function next(){
y=get_nextSibling(y);
if(y!=null){
document.write("<br />nextsibling: ");
document.write(y.nodeName);
document.write(" = ");
document.write(y.innerHTML);
}else{
document.write("<br>已经是最后一个节点");
}
<input type="button" value="next" onclick="next()"/>