How do I pull from within a nested tag with javascript?

Obviously, I'm new to Javascript, and I'm sure that my time with it will be shortlived; this is just for a small project at work. I would really appreciate it if someone would help me figure this out.

I'm trying to set up a page that displays data from an external .xml file, of which I have absolutely no control. It is set up just like this:

<lab id="1" name="A" inUse="14" offline="1" available="16">
</lab>
<lab id="2" name="B" inUse="11" offline="9" available="7">
   <client id="x" status="available" mac="#" ip="#" name="COMPUTER1" />
   <client id="y" status="available" mac="#" ip="#" name="COMPUTER2" />
</lab>

I am displaying the data with a table using the following code:

<%
    try
    {
        URL url = new URL("http://clstats.cc.nd.edu/public/xml-client.jsp");
        InputStream input = url.openStream();
        DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
        Document XMLInfo = builder.parse(input);

        NodeList labs = XMLInfo.getElementsByTagName("lab");

        int length = labs.getLength();
        int i;
        for (i = 0; i < length; i++)
        {

           Node current = labs.item(i);
           String labName = current.getAttributes().getNamedItem("name").getTextContent();
           String available = current.getAttributes().getNamedItem("available").getTextContent();
           String offline = current.getAttributes().getNamedItem("offline").getTextContent();
           String inUse = current.getAttributes().getNamedItem("inUse").getTextContent();
            //Alternate the row colors
            if( (i % 2) == 0)
            {
                  %>
                      <tr style="background:url(#);">
                  <%
             }
             else
             {
                 %>
                 <tr style="background:url(#);">
                 <%
              }
              %>
              <td><%= labName %></td>
              <td><%= available %></td>
                    开发者_如何学Python      <td><%= offline %></td>
              <td><%= inUse %></td>
              </tr>
              </td> 
               <%
        }
    }
    catch(Exception e){
    }

%>

I am having no trouble displaying information from the "lab" tag, but I'd like to only display data from within a particular lab, let's say lab id=2. Is there a way to display attributes from the "client" tags from under a single, particular "lab" tag?

Thanks, I hope I explained the problem well enough. As you can see, I'm pretty much a noob, and any help would be much appreciated.

Intended Result:

<table>
<tr>
<td>Name</td>
<td>Status</td>
</tr>
<tr>
<td>COMPUTER1</td>
<td>Available</td>
</tr>
<tr>
<td>COMPUTER2</td>
<td>AVAILABLE</td>
</tr>
</table>

You are using getElementsByTagName on the XMLInfo to get labs. I think you can also use Nodelist clients = current.getElementsByTagName("client"); then iterate through those nodes.

That looks like java to me in which case I think you could use Xpath like this:

InputStream input = url.openStream();
   DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
   Document XMLInfo = builder.parse(input);

  XPath xPath = XPathFactory.newInstance().newXPath();
  Node myNode = xPath.evaluate("/lab[@id='2']", XMLInfo, XPathConstants.NODESET);

That should get you the individual node.