<body>
<div><b id="oldnode">JavaScript</b>是一个很常用的技术，为网页添加动态效果。</div>
<a href="javascript:replaceMessage()" onClick="replaceMessage()"> 将加粗改为斜体</a>
<script type="text/javascript">
function replaceMessage(){
var ohtml = document.getElementById("oldnode").innerHTML;
var oldNode =document.getElementById("oldnode");
var newNode = document.createElement("i");
newNode.innerHTML = ohtml;
oldNode.parentNode.replaceChild("newNode,oldNode")
}
</script>
</body>replaceChild();里面的内容不用加引号