VBScript、JavaScript判断xml节点是否存在

<script type="text/vbscript">
Dim xmlDoc,node
Set xmlDoc = CreateObject("MSXML2.DOMDocument")
xmlDoc.loadXML("<xml><file/></xml>")
Set node = xmlDoc.selectSingleNode("xml/file")
If Not node is Nothing Then
	MsgBox "存在 file 节点！"
Else
	MsgBox "不存在 file 节点！"
End If
Set node = Nothing
Set xmlDoc = Nothing
</script>

<script type="text/javascript">
var xmlDoc,node
xmlDoc = new ActiveXObject("MSXML2.DOMDocument")
xmlDoc.loadXML("<xml><file/></xml>")
node = xmlDoc.selectSingleNode("xml/item")
if(node!=null)
	alert("存在 item 节点！")
else
	alert("不存在 item 节点！")
node = null
xmlDoc = null
</script>