title: Searching for in an XML file for a specific product id
body: <p>I ran into a problem that i've been trying to solve with no luck.</p>
  
  <p>Im trying to search an XML-file for a specific product id. Following is a snippet from the XML-file.</p>
  
  <pre><code>products xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="xxxxxx"&gt;
  &lt;product articleNo="13000"&gt;
      &lt;name&gt;Fire Brigade Frame HB&lt;/name&gt;
      &lt;category id="6"&gt;Backbacks and bags&lt;/category&gt;
      &lt;languages&gt;
          &lt;lang id="1"&gt;
              &lt;standardProperties&gt;
                  &lt;property name="webHeaders"&gt;Stabil aluminiumram.  Passar otympliga bördor.  Kraftigt höftbälte.&lt;/property&gt;
                  &lt;property name="webText"&gt;Aluminiumram med bärsystem utan säck. För tillfällen när stora otympliga bördor ska flyttas med muskelkraft. Kraftigt höftbälte och remmar för att fästa med. &lt;/property&gt;
              &lt;/standardProperties&gt;
              &lt;extendedProperties&gt;
                  &lt;property name="Webbing"&gt;Polypropylene, aluminium frame&lt;/property&gt;
                  &lt;property name="Djup"&gt;32 cm&lt;/property&gt;
                  &lt;property name="Höjd"&gt;80 cm&lt;/property&gt;
                  &lt;property name="Bredd"&gt;36 cm&lt;/property&gt;
                  &lt;property name="Total vikt"&gt;1900 g&lt;/property&gt;
                  &lt;property name="Yttertält"&gt;1900 g&lt;/property&gt;
              &lt;/extendedProperties&gt;
          &lt;/lang&gt;
  </code></pre>
  
  <p>as you can see in the XML-file there's a /products and a /product which includes an ID, this is the ID i want to search for.</p>
  
  <p>I've been trying with the following code, But It only gives me an error.</p>
  
  <pre><code>$xml = simplexml_load_file("xxx.xml");
  $results = $xml-&gt;xpath('/products[product articleNo=13000]');
  print_r($results);
  </code></pre>
  
  <p>error message:</p>
  
  <pre><code>Warning: SimpleXMLElement::xpath() [simplexmlelement.xpath]: xmlXPathEval: evaluation failed in /xxx.php on line 85
  </code></pre>
  
  <p>line 85 is where the code is placed.</p>
  
  <p>All the best,
  Marten</p>