有没有大神看看我的代码哪里有问题？？谢谢了！
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<title>无标题文档</title>
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<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()"> 将加粗改为斜体</a>
<script type="text/javascript">
function replaceMessage(){
var newnode=document.creatElement('em');
newnode.innerHTML='Java';
var oldnode=document.getElementById('oldnode');
var zz=document.getElementsByTagName('div');
zz[0].replaceChild(newnode,oldnode);
}
</script>
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