求大神告诉我哪里错了
<body>
<div id="con"><p>javascript</p>
<div>jQuery</div>
<h5>PHP</h5></div>
<script type="text/javascript">
var x=document.getElementById("con");
document.write(x.firstChild.nodeName+" "+x.firstChild.nodeType+" "+x.firstChild.nodeValue"<br>");
document.write(x.lastChild.nodeName+" "+x.lastChild.nodeType+" "+x.lastChild.nodeValue"<br>");
</script>
</body>
