insertAfter(newElement,targetElement)函數就是把一個節點插入到另一個節點之後
函數如下:
function insertAfter(newElement,targetElement){
var parent = targetElement.parentNode;
if(parent.lastChild == targetElement ){
parent.appendChild(newElement);
}else{
parent.insertBefore(newElement,targetElement.nextSibling);
}
}