Getting node value from XML string using javascript

I am trying to retrieve the 'code' and the 'value' from an XML string.

I have the following XML string:

<items>
    <item>
            <id>55</id>
            <attributes>
                <attribute>
                    <code>ID</code>
                    <value><![CDATA[55]]></value>
                </attribute>
                <attribute>
                    <code>Chip_ID</code>
                    <value><![CDATA[1]]></value>
                </attribute>
                <attribute>
                    <code>FilterKey</code>
                    <value><![CDATA[5]]></value>
                </attribute>
                <attribute>
                    <code>DateTime</code>
                    <value><![CDATA[22/12/2014 12:21:25]]></value>
                </attribute>
            </attributes>
    </item>
</items>

I then have the following javaScript to identify each node:

       var xmlDocument = new ActiveXObject('Microsoft.XMLDOM');
        xmlDocument.async = false;
        xmlDocument.loadXML(pXML);

        var oFirstNode = xmlDocument.documentElement;

        var item = oFirstNode.childNodes[0]; //10 of these and they represent the items
        //alert("1 "+item.nodeName);

        var ID = item.childNodes[0]; //one of these for each level-ID - NO CHILDREN
        var attributes = item.childNodes[1]; //one of these for each level-attributes
        //alert("2 " + ID.nodeName);
        //alert("2 " + attributes.nodeName);

        var attribute = attributes.childNodes[0];//4 of these for each level and they all have 2 children-code and value
        //alert("3 " + attribute.nodeName);

        var code = attribute.childNodes[0];
        var value = attribute.childNodes[1];

        alert(code.nodeName);
        alert(value.nodeName);

I know I am at the correct node as the alert boxes are all giving the expected values.

I now want to retrieve the text for 'code' and 'value' eg the first entry should return code = ID value = ![CDATA[55]]

I have tried:

            alert(code.nodeValue);
            alert(value.nodeValue);

but they are both coming back null.