如何样可以获得XML里面某项的内容

怎么样可以获得XML里面某项的内容?
比如
<?xml   version= "1.0 "?>
<aa>
<cc   dd= "34 "> dd </cc>
</aa>

怎么样可以获得 <cc   dd= "34 "> dd </cc> 这个的文本信息?

[解决办法]
var xmlDoc = new ActiveXObject( "Msxml2.DOMDocument.3.0 ");
var currNode;
xmlDoc.async = false;
xmlDoc.resolveExternals = false;
xmlDoc.load( "yourXml.xml ");
if (xmlDoc.parseError.errorCode != 0) {
var myErr = xmlDoc.parseError;
alert( "You have error " + myErr.reason);
} else {
xmlDoc.setProperty( "SelectionLanguage ", "XPath ");
currNode = xmlDoc.selectSingleNode( "/aa/cc[@dd=34] ");
alert(currNode.text);
}